# A natural light Walstad tank in the tropics.



## jojo jose (Jul 14, 2013)

*Hello everyone,

This discussion started in the "What is El Natural?" sticky with the post below from Jose. The subject of a natural light Walstad tank in the tropics is so interesting and unique, that I thought it deserved it's own thread. Now if any of our other members in tropical regions want to try this, they can easily find the discussion.

--Michael*

Hi Everyone!

I'm from the tropics where we enjoy stable temps and generally sunny weather all year long. I've recently quit the tedious high-tech, high maintenance, heavily filtered tank concept in prepping for transfer to a smaller place where I cannot bring my large tanks.

This sparked my interest to consider the option of setting up a smaller, more manageable NPT to fill the bill of continuing the hobby of fishkeeping at a more manageable pace. The attraction of really low maintenance is a huge bonus since electricity cost over here is quite expensive. So having no filtration at all is welcome relief!

My main concern is on lighting. The intended place for the NPT is on the outer edge our open garage where the tank will be getting direct sunlight (since it is facing the east) during the early morning hours, and mostly daylight throughout the day till sunset. It is safe to say that at any given day it will receive daylight at least 10-12 hours daily. Low side of the equation during the rainy season.

Is this available "free" lighting enough to sustain plant life that require low/moderate lighting conditions? Or do I need to augment with fluorescent lighting during the evening hours? By the way, I am initially doing the NPT on a 5gal and 20gal tank I have lying around after I sold my large tanks. Once I get through the learning process I may consider setting up at least a 50gal NPT once I move to my new place.

My other concern is the issue of water parameters. I never did own any water test kit in the past doing the high-tech filtered setups. I just did a prudent job of regular WCs to keep things in order. It seemed to keep my fish happy but it is back-breaking work to say the least!

How can I get by with the low-tech NPT without having to invest in a test kit? What kind of WC regimen will it need during the initial setup?

I do look forward to all inputs!

Cheers!


----------



## Michael (Jul 20, 2010)

*Re: What is "el Natural?" A Step by Step?*

Jose, welcome to APC and the Walstad method!

My guess is that you will have plenty of light. In the tropics you will not have the seasonal fluctuations in day length and sun angle that make it difficult to use only natural light here in the temperate zones. We have trouble because the natural light is so inconsistent from one season to another.

It would be a great idea to set up your smaller tanks in the location you plan to use for the 55 as tests. That way you can see how the plants (and the algae) grow before the big one goes in, and maybe adjust the location.

I don't own a test kit, but when I start up a new tank I can take water samples to my local fish store and have them tested for ammonia, nitrite, and nitrate. Unless you have difficult tap water to begin with, or are planning to keep sensitive fish and plants, these are the only tests you really need to do. I take samples in until the water tests safe for fish, then I never test it again.

How much you need to worry about ammonia etc. depends greatly on what type of soil you use. Highly organic soils with lots of nutrients tend to produce ammonia spikes in the first month. You can read a lot more about this in the sticky thread, "Suitable soils for the Walstad method".

I suggest that you use a filter with lots of biomedia in it. It will give you an extra margin of safety if anything goes wrong, and it will circulate the water. Circulation is important in Walstad tanks. If you don't want to use a filter, use a power head at least.

This makes me wonder if you could use one of those solar-powered pumps sold for small outdoor fountains. It wouldn't help at night, but would keep the water moving during the day. Maybe a solar pump during the day, and a conventional power head at night if needed?


----------



## jojo jose (Jul 14, 2013)

*Re: What is "el Natural?" A Step by Step?*

Hi Michael,

Many thanks for the warm welcome! The test location for my smaller tanks is no more different from where I intend to place the 50gal NPT once I move to the new house. By way of natural lighting I will get generous amounts of daylight most of the day, and only an hour's worth of direct sunlight. I am excited to find out if this will work, though many local aquatic plant keepers suggested I keep "easy" plants that thrive well in low lighting conditions in order to assure success.

The tap water is fairly hard to neutral PH so it should be easy on the plants, endemic soft water fish species also thrive well. It is only the wild caught imports that encounter survival issues.

Now on the matter of soil composition, I'd like to say what I have on hand should be on the moderate side. I followed some advise to use top soil in which grass is already growing in order to avoid having too much organic nutrient content. I just added a small amount of regular topsoil from a local landscaper which is also natural minus the added chemical/organic fertilizers. The whole mix is presently soaked in water on a basin in the hope of dissipating/rinsing the potential toxins before use in the NPT. I read to do this soak for at least three days and even dry it totally in order to come up with "mineralized soil" so to speak.

On the matter of circulation, since I only have the smaller tanks, I do recall mechanical circulation being recommended for the larger tanks only? I can use one of the smaller sub pumps lying around for the initial setup in order to add some level of safety. I do appreciate its worth having the pump running at night being more important. But here's the curve ball... If I put lighting at night, would this help avert the expected oxygen deficit minus the lighting?


----------



## Michael (Jul 20, 2010)

*Re: What is "el Natural?" A Step by Step?*

Easy plants are always good to get the tanks started. Once the tanks are stable, try some more difficult ones

The soil sounds good.

You can't leave the lights on for oxygen all the time--both plants and fish need a dark period. And circulation does much more than aerate the water. It keeps all the nutrients evenly distributed through the tank, and helps dissipate other gases that may build up in the water. I think it is really helpful in all sizes of tanks.


----------



## jojo jose (Jul 14, 2013)

*Re: What is "el Natural?" A Step by Step?*

So much for the lights on at night! I follow the need for having circulation in the water column, fortunately my spare 20gal has a built in sub pump and OHF to do the job. However, if I have to operate it full time then I run the trouble of rising temperatures in such a small tank. Even my 100gal tanks with full-time filtration get quite warm compared to ambient conditions in my unfiltered fish tub.

I guess this would be less of an issue if I put a really small sub pump in the 50gal setup just to stir things up. But again will the small amount of circulation be acceptable over none? Can I operate the sub pump in the 20gal tank for night only to avoid heat up?

By the way, once I get some level of agitation with the OHF/sub pump in operation, would this somehow affect the levels of CO2 in the tank which I believe is for the plants benefit? I always thought agitation oxygenates the water column. Pardon the newbie queries since I am only beginning to realize the finer points of the NPT...

I hope you and others will have the patience to bear with my teething stages!


----------



## Michael (Jul 20, 2010)

*Re: What is "el Natural?" A Step by Step?*

Some circulation is better than none.

It helps to remember that O2 and CO2 levels are not antagonistic. In other words, you can have high levels of both, low levels of both, or high levels of one and low levels of the other.

To avoid losing CO2, arrange the filter or power head so that there is no splashing or bubbling at the surface of the water. Movement at the surface is good, but just gentle ripples, no splashing. In this way you retain CO2 while still having the benefits of circulation.

As long as water in the tank is circulating as described, CO2 levels will remain in equilibrium with the atmosphere or higher. Now this level might not be as much as we (or the plants) would like, but it will never be zero. A tank with no circulation, few fish, low levels of healthy decomposition, and lots of actively photosynthesizing plants can be depleted of CO2 by the plants.

I can't help much with the heat problem. Like so many things in planted tanks, this will be a question of balance between the benefits of circulation and the problem of heat build-up. Better quality, more efficient pumps might help a little--they should produce less heat and use less electricity.

You never need to apologize for thoughtful questions. Just out of personal curiosity, where in the tropics are you located?


----------



## jojo jose (Jul 14, 2013)

*Re: What is "el Natural?" A Step by Step?*

Hi Michael,

I'm from the Philippines! Where it is either sunny or rainy, ambient temps at 25-30deg C most of the year and horribly 33deg+ C in the summer months.

Now I gain a better appreciation of water circulation after you threw in the specifics! These are the intricacies of a planted tank I am only beginning to find out. Well this is becoming more of a challenge and an exciting venture into the unknown for someone like myself. At least thanks to the information superhighway I can always make a very well informed decision from experienced keepers like you! The only unknown being the outcome of my project!

I suppose for the time being I already have the "tools" to at least get things off the block. The soil soak is almost done. I shall begin purchasing/setting up the plants/fish soon on my next day off. Having a day job really sucks. It steals a lot of quality time from the more important things in life like hobbies and bumming around!


----------



## Michael (Jul 20, 2010)

*Re: What is "el Natural?" A Step by Step?*

Take at look at this thread for suggestions on circulation: http://www.aquaticplantcentral.com/forumapc/filtration/88242-how-setup-proper-water-flow.html


----------



## jojo jose (Jul 14, 2013)

*Re: What is "el Natural?" A Step by Step?*

Hi Michael,

As of this writing, my first attempt on NPT with my 20gal tank is around 24-hours old. I did not mineralize the topsoil any further since it came from a grassy lawn so excessive nutrient/organic content may not be an issue anymore.

I got the "easy plants" from a local LHS which had very limited stocks available. They were not in the best shape and form as some had crooked stem growth from possible mishandling or being kept in less than favorable conditions. I settled for them since this is more of a test project anyway. After setting them up in the tank, the entire thing looked like it was hit by an F5 tornado! Not exactly the most pleasant thought of a planted tank by any means...

However, the "easy' part somewhat lived up to its reputation. I notice that after only a couple of hours, the plants began to straighten out and take on a more stately and lush appearance. More so this morning when most of the withered look has mostly gone. I can only assume how much improvement to expect after a week when I already see something in a day's time!

Pardon the ignorant overwhelmed expression of delight from a total newbie into NPT as my only other experience regarding plants was during elementary school after planting beans for a science experiment. Moving forward, I am eager to find out if the setup will encounter algae blooms once it ages. I hope the natural daylight it receives is adequate to sustain plant growth and keep algae at bay.

Cheers!


----------



## Michael (Jul 20, 2010)

*Re: What is "el Natural?" A Step by Step?*

No apologies necessary! When I was a kid keeping aquaria eons ago, what I really wanted was a planted tank. But almost no information was available--this was WAY before the internet, and you can imagine how many books on planted tanks were around in Wichita, Kansas in the 1960s.

Forty years later when I set up my first Walstad tank, I was almost giddy because of how well it worked. So I know how you feel!


----------



## jojo jose (Jul 14, 2013)

*Re: What is "el Natural?" A Step by Step?*

On the matter of water circulation, can I get by running the powerhead at night only? I assume day time would pose no/less risk since the plants should be producing the O2 and not compete with the fish unlike during night...


----------



## Michael (Jul 20, 2010)

*Re: What is "el Natural?" A Step by Step?*

Honestly, I think the circulation should be on 24/7. Yes, in the daytime plants are producing O2 and not competing with fish for it. But there are other important benefits of circulation--such as distributing nutrients throughout the tank, not allowing areas of low oxygen to develop, and maximizing the biofiltration by plants and bacteria--that are needed during the day as well.


----------



## jojo jose (Jul 14, 2013)

*Re: What is "el Natural?" A Step by Step?*

I may need to find a smaller pump to handle water circulation without the added heat generated by the slightly larger pump. Now I miss the 100gal tank for sheer water volume!

The next thing that really hits my buttons is the issue of lighting, or lack of it! I believe the "easy" plants get by on low to medium lighting as per LHS advise. As I would like to take advantage of my outdoor (garage) setup that gets mostly daylight and minimal direct sunlight (only 1 hour in the morning), is daylight qualified to be within the medium lighting range? What would be my reckoning to find out if I need to augment lighting by way of fluorescent PL, etc? For the time being, at barely three days old, the plants seem to be doing well without any signs of yellowing on the leaves, as I would guess is the result of inadequate lighting...


----------



## Michael (Jul 20, 2010)

*Re: What is "el Natural?" A Step by Step?*

Let's summarize your conditions. Please correct any mistakes.

1. You are in the tropics.
2. Tank is located at the edge of covered carport, with an eastern exposure, giving one hour of direct sunlight and 10-12 hours of indirect sunlight every day.
3. There is no window glass, insect screen, shade cloth, foliage of trees, etc. between the tank and the sky to the east.

I think you will have plenty of light, possibly more than you want.

It will take a month before you really know how the plants are doing. They must first recover from transplanting, shipping, bad conditions at the LFS, and everything else. In the first few weeks, your plants may show all kinds of symptoms related to stress. They may turn yellow, drop leaves, fail to grow.

The first plants to show symptoms of low light will be fast growing stem plants. They will stretch toward the light, stems will be long and thin with leaves widely spaced, and the lowest leaves may fall off. But give it a month before you worry.

Because you have a unique situation, I will probably start a new thread for you and move most of these posts to it. That way if anyone else wants to do a Walstad tank in the tropics with natural light only, they will be able to find this discussion. Please keep us updated!

Look for the new thread: "A natural light Walstad tank in the tropics."


----------



## jojo jose (Jul 14, 2013)

Thanks for starting a thread on my behalf. Hope this will be of any help to anyone in the same boat as I am.

Good to know I need not hit the panic button yet! I will just observe for a month's time and see how things unfold. Your assessment of my available daylight is dead-on. I have a fish tub that's been running for almost two months with heavy algae growth near my 20gal NPT. So I guess I may have more than enough natural lighting to sustain my "easy" plants.

Here's a couple of pictures taken after barely three days from setup:

The shot below was taken at 0800H. From the shadow of the wooden stand you can see it is receiving direct sunlight in the early hours between 0600-0800H the morning. 









The shot below is a humble close up of the "easy" plants. At the moment there's a male guppy and two zebra danios out there to provide much needed "support" for the plants. 









Unfortunately, I did not take a shot of the setup in day1 when everything looked like it was hit by an F5 tornado! They seem lot better now compared to the wilted, droopy look they had three days ago. This may not win any awards in a show with the random, hasty manner I plugged them into the substrate. But I am quite happy at the way things are moving on so far...

The photos have no artificial lighting, just direct, morning sunlight. It is pretty much this way even later in the day without the direct sunlight. Things only start to taper down later in the afternoon.

I guess this would be all for now. I shall post pictures later as things develop...


----------



## jojo jose (Jul 14, 2013)

*Again on the issue of water circulation...*

From what I recall on heavily filtered "high tech" setups, you need at least 3X the tank volume in water turnover to achieve an acceptable level of movement necessary for efficient filtration. So for a 100gal tank, the rate of 300gal/hour is required as I would remember. Higher turnovers being necessary for cichlid or goldfish tanks due to the higher bio-loads...

Since the NPT also benefits from circulation as you advise, what is the minimum I can get by in turnover rate? I plan to use a basic submersible pump with inlet on one end with plumbing for the outlet all the way to the other end when I start the larger setup with a longer tank once I move to the new place. I say minimum since it would be nice to achieve the necessary movement without agitating the water column too much like what I had in the previous filtered setups. Not to mention the lower cost of running the smaller pump...


----------



## jojo jose (Jul 14, 2013)

On ammonia:

I recall reading somewhere in the NPT threads ammonia and nitrite being preferred over nitrate by plants. In the ideal world, does this stop the nitrogen cycle dead on its tracks once the plants consume the available ammonia in the water column? I just thought this is the logical realization since nitrites/nitrates are by-products of the nitrogen cycle anyway. What is there left to cycle once the ammonia is gone?? 

Also, it is my understanding that plants also consume nitrates as well that is why plant filters are highly recommended in high-tech heavily filtered setups. Hence reducing the frequency of water changes in order to keep nitrate levels acceptable to nil...

Since you suggested to observe my newly setup NPT for at least a month to stabilize, is it possible to expect very low to NIL values of ammonia, nitrite, nitrates moving in a month's time? To date, at one week old, the Indian fern which I guess is the fastest of the "easy" plants is obviously moving/growing compared to the others. It is developing roots from some of the stems and visible leaf growth can be seen on the tops...


----------



## Michael (Jul 20, 2010)

Circulation: Take a look at this thread http://www.aquaticplantcentral.com/forumapc/filtration/88242-how-setup-proper-water-flow.html We actually have tried to get 8X to 10X the tank volume per hour, but it may be more important to set the circulation up as described in that thread, so that all areas of the tank benefit.

Ammonia: Plants do prefer ammonia, but as a practical reality a new Walstad tank usually has ammonia levels that are high enough to support and require a "cycle". In an ideal situation (heavily planted tank, healthy plants absorbing ammonia as fast as they can, good circulation) there may not be enough ammonia present to need a cycle. This is why Walstad herself puts fish in the tank right away. But she is an expert!

It is possible that your tank will not need a cycle (i.e. ammonia and nitrite levels near zero) but I would not bet on it. It helps a great deal to include lots of fast growing stem plants and floating plants in a new tank because they absorb ammonia quickly.


----------



## pweifan (Jun 23, 2007)

This will be fascinating to watch and see what happens. Welcome to APC and good luck, jojo jose!


----------



## jojo jose (Jul 14, 2013)

pweifan said:


> This will be fascinating to watch and see what happens. Welcome to APC and good luck, jojo jose!


Thanks for the kind words! I'm posting pictures soon to note any developments... or lack thereof!=P~


----------



## jojo jose (Jul 14, 2013)

Algae Issue:

Hey Michael,

At almost 10 days from day1, I am beginning to see some algae growth on the pebble/gravel stones, on the dirt substrate layer you can see algae developing on the inside glass, on the leaves of some of the "slow" plants also. I think this may get out of proportion sometime unless I nip it in the bud ASAP. 

However, there is no algae growth on the inside glass except that seen through the dirt layer only. I guess more plant material is necessary to absorb the excess nutrients? Let me know your thoughts...


----------



## jojo jose (Jul 14, 2013)

Real Algae Issue!

After a much "closer" second look, there is actually algae developing on the glass panels as well. It is just subtle enough of a bloom that you barely see it. I am also seeing some amount of bubbles forming in between the pebble grains cap layer over the dirt base. It seems there is much going on now that the algae has arrived!

So do I really need to plant "heavily" at this juncture? I think I should have gotten more if not all Indian fern as they prove to be the really fast growing ones.

For the bacopa and other types that had algae growth on their leaves, are they still good to go? Or are they doomed to a dire fate in plant heaven?


----------



## SBS (Feb 26, 2013)

What type of algae is this? Do you have pictures? If it's brown diatoms, then this could be because first the tank is new and the stats are not stable, possibly ammonia plays part. And second, you may have too much light. Removing the fast growers at this stage is not desirable. Try reducing the light period and light intensity if possible as this is the major factor.


----------



## jojo jose (Jul 14, 2013)

SBS said:


> What type of algae is this? Do you have pictures? If it's brown diatoms, then this could be because first the tank is new and the stats are not stable, possibly ammonia plays part. And second, you may have too much light. Removing the fast growers at this stage is not desirable. Try reducing the light period and light intensity if possible as this is the major factor.


I shall post pictures once I get the chance...

It is brown as you imply since this is a new setup. If high ammonia is the culprit, what kind of manifestation would it have on fish behavior? So far the fish have not been exhibiting anything out of the ordinary. I would like to suspect it may be too much light if not ammonia. Although I am relying on the premise of having an NPT with natural daylight on an outdoor environment, perhaps I may actually be getting more natural daylight than I really need.

So if you suggest reducing the light intensity, I may just have to move the tank a few notches indoors from its present position and observe once again.

I shall also add more of the "fast" plants for assurance!


----------



## Michael (Jul 20, 2010)

You are entering uncharted territory. I suspect that any outdoor tank is likely to have algae on the glass. But having growth of algae on the glass that is only seen by looking closely is not excessive.

You may have too much light AND excess nutrients since this is a new tank. The first thing to try is more plants, and especially floating plants like water sprite, water lettuce, water hyacinth, frog bit, and red root floaters. These shade the surface and reduce light while using excess nutrients. Also, you may need to move the tank into more shade, as you mention in your last post.


----------



## SBS (Feb 26, 2013)

> If high ammonia is the culprit, what kind of manifestation would it have on fish behavior? So far the fish have not been exhibiting anything out of the ordinary.


Most times the ammonia causing brown diatoms is not even high enough to be detected on a home test. Most fish, if not all can withstand that amount just fine because those levels aren't exactly toxic, at least not in short term. Just clean it up and do some more regular water changes for now. Since brown diatoms consume that ammonia in the presence of light, it's like your tank is in self defence mode. The point is the ammonia gets consumed one way or the other. As your tank matures, the diatoms will be outcompeted by plants and filters instead.

Also, brown diatoms is very common in new tanks and normally stops growing itself in a few weeks. Of course one may need to clean up a bit in the mean time as it may smother the plants, but make sure you don't just let it float in the tank after cleaning as it re-attaches itself. I've used kitchen towels for the glass and my fingers for the plants, but then do a water change to remove the floating bits.
Excessive light will cause excessive bloom, and possibly once the diatoms are gone, if light is still higher than handled by the tank, a nastier algae can apear. Hence its better somehow reducing the light intensity just in case. Other than that, I'd just wait it out patiently as it will run it's cycle. Many fish also eat diatoms but maybe not fast enough. One of those that really love it and can strip down the tank from it are otocinclus but then they are sensitive to new tank conditions at the same time.


----------



## jojo jose (Jul 14, 2013)

Many thanks for the inputs! I guess this is a typical case of the NTS blues as with a regular high-tech filtered setup. 

I realize there may be a concern for "too much" lighting in this uncharted territory as Michael would like to suggest. I am equally surprised if this were actually the case since I am only getting regular daylight and not direct sunlight! Furthermore, these recent past few days were generally cloudy hence reduced light intensity for the most part. I do turn on the tank lighting for relatively brief periods when I view the tank but I guess not long enough to cause a major bloom!

I shall reposition the tank to reduce lighting levels. My only trepidation over this move is whether the "low" light conditions satisfy the plant needs in order to survive.

I suppose the occupants (3 guppies, 2 zebra danios) can weather out the cycle since they are relatively hardy fish. On the issue of excess nutrients I shall add more of the fast plants and see where it goes from there!


----------



## jojo jose (Jul 14, 2013)

SBS said:


> Also, brown diatoms is very common in new tanks and normally stops growing itself in a few weeks. Of course one may need to clean up a bit in the mean time as it may smother the plants, but make sure you don't just let it float in the tank after cleaning as it re-attaches itself. I've used kitchen towels for the glass and my fingers for the plants, but then do a water change to remove the floating bits.
> 
> Excessive light will cause excessive bloom, and possibly once the diatoms are gone, if light is still higher than handled by the tank, a nastier algae can apear. Hence its better somehow reducing the light intensity just in case. Other than that, I'd just wait it out patiently as it will run it's cycle. Many fish also eat diatoms but maybe not fast enough. One of those that really love it and can strip down the tank from it are otocinclus but then they are sensitive to new tank conditions at the same time.


On the brown diatoms, I have scrubbed whatever is seen visible on the glass panels. I will just run the filter to suck them out of the tank. They are not "chunky" enough for me to grab them physically out of the water column.

I am more concerned with the stuff that grew on the plant leaves (bacopa) since I cannot remove them by hand. Will this mean certain doom? Or can the bacopa ride it out once I reduce lighting?


----------



## SBS (Feb 26, 2013)

No, it needs manual removal. Try cleaning the leaves with your fingers gently. In the worse scenario, just cut the affected parts off. The bacopa should grow anyway to the point of trimming but if all leaves now are covered, it will suffer. The other option is to invest in a few ottos if you are willing. They are good for a planted tank long term but can be sensitive if the tank isn't stable. I did add ottos to mine when it had ran just for a couple of months with no issues but who knows... They are best drip acclimated before adding to the tank. They clean brown diatoms like they didn't exist.


----------



## jojo jose (Jul 14, 2013)

*Dismal Update!*

After being out for close to two weeks, I found the 20gal tank riddled with algae, two guppies in near death (now dead) condition, and only two unidentified plants up and running with the bacopa. Hydrilla all looking pale and limp. I decided to reset the whole thing by potting the good plants and transferring them in my running NPT tub (which incidentally is doing pretty darn good).

What concerns me the most is when I dug up the gravel cap, I notice the dirt bottom layer is quite tough, compacted and thick compared to the gooey mud it was during day1 setup time! If this is the case, I think rooting for the plants can become an issue??? Is this supposed to be the case?

On the 35gal tub I set up more recently, I had the plants rooted in individual plastic drinking cups with the same dirt and gravel cap as the 20gal tank. So far, I can still feel some "give" when I squeeze the plastic cups, hence the dirt layer may still be loose...


----------



## niko (Jan 28, 2004)

If you find a way to do the following two things your tank will have zero issues:

*1. The substrate should not compact.*
It should allow water to flow through it. That's very important because if you are not using a filter your substrate is the filter now. And it will both convert (a)Ammonia to Nitrate and (b)Nitrate to gas N (N disappearing in thin air, out of your tank!). Both (a) and (b) completely depend on the water being able to flow through the substrate.

*2. There should not be any accumulation of organics in the tank.*
Efficient filtration will take care of that. But that means that you need to have a biofilter that is 10-50% of the volume of the tank. Without a filter the best way to achieve that is to do small and frequent water changes - 10-15% every 2 days AND not have too many fish (one guppy in 10 gallons is ok, but not more).

The idea of the small and frequent water changes is to remove organics (made by both plants and animals in the tank). But there is a long-term goal too - the tank is most unstable in the first 3-8 months. If you keep it running clean during that period it will eventually come to a state where it maintains itself clean and the water changes are not needed. But you have to have a substrate (filtration media) that does not clog.

Keep in mind that what YOU are trying to do (natural light and no special electric filter) is what Nature does. What WE all do (filters, lights, etc) is a forced approximation of Nature. Do you think that a tank like yours is possible to achieve? Yes it is. But you need to be observant about how things happen in Nature. The first thing to note is that in the open sea water where the sun shines strong all day long there are zero algae because there is no food in the water. The second thing to do is to admit that in Nature plants grow in water void of nutrients because they feed from the substrate. The usual case in the USA is a tank that has N=10-20 and P=0.5-2.0. In Nature that is water that has been severely polluted. Plants can eat from the water and grow super fast and pretty. But how do they grow in Nature? Eating from the substrate AND a minor amount of food from the water.

I don't think that many people pay attention to the fact that all that our plants try to do, every day, is to get OUT of the water - to get in a situation in which they have their roots in the substrate and everything else is in an environment that does not support competition (air). What happens to algae in air where there is no moisture and no food for them? Zero algae. That same thing could be done under water too if the water was void of nutrients or very low in nutrients. You can do that but the tank will still develop algae. Nutrients in the water or not in the water are not everything. What I talked above (1 and 2) are the first two things toward emulating Nature and establishing a true Nature Aquarium.

Keep in mind that in Nature there are vast areas that function as filters. There are zones of aerobic (Ammnonia --> Nitrate) and anaerobic (Nitrate to free N). There are conditions for all kinds of microorganisms to grow and assimilate everything that we call "waste". The turbulent water in a creek foams up the water and the creek is now a freshwater skimmer. Certain microorganisms can actually remove the organics that cause algae in a tank that is void of fertilizers. Basically filtration is everything! The question is how to set it up right. Read what biofiltration does in the link below:
http://www.aquaticplantcentral.com/...1-biological-filtration-translated-dutch.html

Also, specifically about flow through the substrate read the what "corsair75" has to say about no-filter tanks on this page:
http://www.aquaticplantcentral.com/forumapc/aquascaping/78428-natural-method-vs-style-5.html


----------



## jojo jose (Jul 14, 2013)

Hi niko,

I fully appreciate the information on how significant the substrate level is to achieve biofiltration. What I would like to address and possibly solve is how to keep the bottom dirt layer which was previously slushy mud on day1 from compacting 4-5 weeks down the line. I am thinking since the much finer particles of the slush has the tendency to compact over time, maybe it would be better to have it mixed with coarser gravel to prevent it from compacting??? 

Even for regular gardening, tilling the soil to keep it from compacting certainly helps in cultivating plants. I also thought the same would be true for keeping plants in an aquatic environment...


----------



## Michael (Jul 20, 2010)

The soil in Walstad tanks usually becomes pretty compacted and clay-like over time. This is one of the reasons I recommend a relatively thin soil layer (1 to 1.5"). I also like to mix the soil with one of the porous, high cation exchange capacity substrates, like Turface or Safe-T-Sorb.

Since you are in the Phillippines, I don't know if any of these products are available. So you could try coarse gravel, or small lava rock, pumice, or haydite (expanded shale) if those are available. Haydite is used in construction as a light-weight aggregate for concrete, so you might find it with concrete supplies.


----------



## jojo jose (Jul 14, 2013)

Michael said:


> The soil in Walstad tanks usually becomes pretty compacted and clay-like over time. This is one of the reasons I recommend a relatively thin soil layer (1 to 1.5"). I also like to mix the soil with one of the porous, high cation exchange capacity substrates, like Turface or Safe-T-Sorb.
> 
> Since you are in the Phillippines, I don't know if any of these products are available. So you could try coarse gravel, or small lava rock, pumice, or haydite (expanded shale) if those are available. Haydite is used in construction as a light-weight aggregate for concrete, so you might find it with concrete supplies.


"Over time" as you suggested came in barely over a month from the time I had it set up. From the slushy mud it was I never thought it could toughen up to become so compacted! When I dug it up it was so compacted to the point I wouldn't think rooting through will be possible. Nothing you mentioned sounded familiar to me in the form of porous materials. In my case, the only practical option is to use coarse gravel in the mix.

From the time of setup, I almost wanted to suspect something like this may happen. My only consolation is that resetting a 20gal NPT test tank is easier than a 100gal nightmare!

By the way, is kitty litter an acceptable option to mix in with dirt? I saw this during one of my trips to the local pet-shop...


----------



## Michael (Jul 20, 2010)

Oops, I forgot the cat litter! Yes, it works well, but you must get the plain clay type. No perfume, clumping agents, antimicrobial agents, odor absorbents, etc. Fortunately, plain cat litter is usually the least expensive kind.


----------



## jojo jose (Jul 14, 2013)

Michael said:


> Oops, I forgot the cat litter! Yes, it works well, but you must get the plain clay type. No perfume, clumping agents, antimicrobial agents, odor absorbents, etc. Fortunately, plain cat litter is usually the least expensive kind.


Hi Michael!

After a trip to the local pet shops, here's what I learned:

1. From your description above, the closest thing I found is on the link below:
http://www.purapet.com/ashapurite-non-clumping-cat-litter.html

It states on the label that it is non-clumping, traditional and made from "clay" materials. Nothing added by way of chemicals, etc.

2. I also saw from the same manufacturer a special clumping bentonite material, see link below:
http://www.purapet.com/premium-moonlight-cat-litter.htm#moonlightultra

By the looks of it, item #1 looks like the best option, being non-clumping. Let me know your thoughts since I think item #2 also seems acceptable if not for the clumping properties...


----------



## Michael (Jul 20, 2010)

#1 looks good. I wish the pet supply companies in the USA would give such useful information.

The bentonite in #2 has interesting properties, but probably is not a good idea in aquaria. When it gets wet, it swells and becomes very sticky and impermeable to water. It can actually be used to seal outdoor ponds without the use of a synthetic liner.


----------

