# Longevity of El Natural tank



## Jeffersuan (Mar 20, 2012)

I've been seeing varying opinions on this, and there doesn't seem to be any detailed discussion on this topic alone, so I hope this thread could be of use to the community.

So the main question: What is a reasonable lifespan to expect out of a NPT before plants stop growing?
Related question: How can we increase the longevity of our NPTs?

I have a tank I started about 3 years ago, and for the past 6-8 months I have noticed significant decrease in rate of plant growth, and my water lettuce isn't even proliferating any more. I have been battling BBA, so this might have something to do with it.

Is the slowing growth normally due to light issues, or lack of nutrients, or what?

Lack of nutrients seems the most logical to me, and if this is the cause, how to solve this problem without the need for regular fertilizing? From what I remember from my original research in the Walstad method, Diana said this kind of set-up was virtually infinite, with the plants getting all the nutrients they needed from the fish waste and uneaten fish food. Am I wrong?

Thanks!


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## Moose-Factory (Feb 13, 2008)

I set up a NPT 55 gallon in 2008, on which I've done absolutely no maintenance except top up the water, prune plants, and feed the fish. Right now, the tank seems to be on its last legs. I've got some kind of lilly still alive, and java moss is taking over. The last fish died about a month ago, but the shrimp I've had for about 5 years seems to be doing fine. The tank is at my parents, which is why I let it go (I can only get to it once every 6 weeks or so). 

The tank grew like bonkers the first 2 years or so, and seemed to be in a relatively stable state the next 3 years after that. Then a slow, consistent decline. About three years in, my original florescent light strip burned out, and I only replaced it with CFL table lamps I had at the house, and hung them haphazardly over the tank- that's definitely when the tank stopped "thriving", but that was 3-4 years ago already. I also stopped feeding after the last fish died, so there went any residual fertilization for the remaining plants. I never did any water tests or changes, nor dosed with anything ever after setting up the tank.

In the next few weeks, I hope to salvage the moss, the lilly, and the shrimp for my new tank, which is actually at my house and that I intend to seriously take care of. 

But for my 1st tank that I abused so badly, seven years was a good run! I don't know if it was the lighting, the fertilizing, or the substrate finally giving out that did it in, who knows. I may have actually been able to salvage the thing a year or two ago if I had tried.


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## 1077 (Nov 7, 2011)

Jeffersuan said:


> I've been seeing varying opinions on this, and there doesn't seem to be any detailed discussion on this topic alone, so I hope this thread could be of use to the community.
> 
> So the main question: What is a reasonable lifespan to expect out of a NPT before plants stop growing?
> Related question: How can we increase the longevity of our NPTs?
> ...


Can dose estimative index at rate of maybe 1/3 that used by high tech folks once a week.
My tanks are all soil based tanks or plain sand and modified EI for low tech has worked well for these tanks.
Have also expierimented with soil,cat litter,peat mixture, capped with sand to get a bit more life from the soils In addition to adding the dry mineral salt's once a week.
All tanks get water change each week just like I have done for four decades of caring for fishes.


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## Jeffersuan (Mar 20, 2012)

Regarding dosing ei, I read somewhere that with infrequent water changes, K is really the only fert that is needed in a planted tank. And I'd like to stay with my couple-times-a-year water changes, if possible.

What about carbon? I was doing a bit of research about light vs carbon. The more light a tank gets, the more carbon it will need to keep growing healthy. The less light, the less carbon. Is that basically true?


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## walzon1 (Feb 24, 2014)

I think the key you are missing is BalancE, and it can't be emphasized enough. In a tank that is balanced there is no need for dosing anything. If you have too much light the plants will use all available nutrients and suffer. If there is not enough fish waste, decaying plant and food detritus and lacking oxygen, available nutrients will not be replenish fast enough to feed plants. 

In a new aquarium you start from ground zero and there is no organic waste breaking down cause everything is clean and new. To avoid this, dirt that already has organics is added to quick start the process. These organics are used up over time but during this period there should be a steady supply of fish food and plant decay added to the tank replenishing the substrate with fresh organic waste. If the correct balance of light, fish and plants is attained the cycle can go on forever.


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## Jeffersuan (Mar 20, 2012)

I will try making a few tweaks, and see what happens.

There is also so much mulm in the tank that there is a light dusting on most of the plants, so I guess that could be affecting their photosynthesis ability. Anybody have this problem before? Any way to avoid it (besides frequent water changes)?


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## imported_dukydaf (Aug 2, 2005)

I had some El Natural setups, most of them taken apart before the end of the substrate lifetime. For most of them I would say 2 years depending on the needs of the plants and the richness of the substrate.

However in a 60G I had a mixture of mineralized dirt and some JBL mineral enriched clay, topped with river sand. The setup was mid-high light , pressurized CO2, some liquid ferts. E. amazonicus, cryptocoryne sp and Nymphea sp grew great, and also almost all stems. For about 3 years the plants had a "pink-bunny" battery in their roots. After 3 years I felt the productivity of the substrate declining but was able to maintain it with root tabs, fert sticks for plants and fert clay balls for pond lylies.

Due to certain life changes, switched to low light,low/no CO2, closer to Walstad's model of aquarium. 10 years after the aquarium start 
E amazonicus still sends out "babies",
Cryptocorynes sp grow well,
Nymphae sp. grow a little less and smaller (good for me) 
Sagitaria subulata and H.corymbosa manages to take over the tank.

As you can see most of the plants that grow have very good root systems, but the aquarium receives attention once or twice per year when I go to my parents. Bottom-line with root fertilization you can prolong the lifetime of your El Natural. I attached some before and recently photos

Regarding the "tanks that are able to run to infinity"...RANT
I do not believe that we will ever be able to make our aquariums do that, just because we want more than one fish and a few barely surviving plants. In nature a lot of other creatures beside fish interact with the aquatic environment, the surrounding are also has a huge impact on the nutrients available in a lake. One species of plants dies and another rises or just algae for a time (we would not keep a time during that time). Not to mention the fish/litre in the aquarium and in the lake/river. NASA was able to make something like a self contained aqua ecosystem but I wouldn't want it for my aquarium. What comes out of fish does not contain everything needed for good plant growth. If you feed your fish why not feed the plants as well ? A good thing about soil is that it can "reabsorb" the nutrients and thus stay in the aquarium more.How fast the nutrients in the substrate deplete depends on how fast you want your plants to grow and what plants you grow.


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## 1aqumfish (Jul 28, 2008)

This tank has been running for about five years now, I broke all the Walsted method rules (third dirt tank) but I is going great. When the sword plants start to atrophy I add root tabs. I don't see it as unsustainable you just have to choose how to feed the plants.

[URL=http://s567.photobucket.com/user/1aqumfish/media/CAM00117_zpsf6rtwiwj.jpg.html]


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## 1077 (Nov 7, 2011)

Jeffersuan said:


> Regarding dosing ei, I read somewhere that with infrequent water changes, K is really the only fert that is needed in a planted tank. And I'd like to stay with my couple-times-a-year water changes, if possible.
> 
> What about carbon? I was doing a bit of research about light vs carbon. The more light a tank gets, the more carbon it will need to keep growing healthy. The less light, the less carbon. Is that basically true?


Yes,lighting drives demand for everything in the planted tank.


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## Eutexian (Mar 29, 2015)

I have no idea how long a 'dirted' tanks substrate will last. however on page 140 of 'ecology...' Walstad says she has tanks that are (or were) 6 and 8 years old and 'continue to do very well'.

To my mind the actual length of time doesn't really matter.. its far more likely i would strip a tank down to restart it, not because the dirt was exhausted.. but simply because i fancied a change.

As far as I can tell the duration of time a dirted tank lasts is more dependent on my 'lack of involvement' than anything else. so for me that means never cleaning the gravel.. except in a very minor way.. the very front of the tank particularly. and to an extent overfeeding. so as well as fish poop there is also a certain amount of fish food that escapes detection - falls into the gravel where its converted from organic matter to inorganic 'plant food' - with the nice side effect of co2 produced. so win/win.

my current tank is only a little over 10 weeks old, so this is hardly a concern right now.

But.. it'll be interesting to see if the plants continue to do well.. with nothing added to the 'system' aside from fish food and the occasional water change.

my 'jungle' Barb paradise today.


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## pandragon (Jul 10, 2014)

I have had a 30g npt up approaching a year now. I used inert clay to make hills and such with a small layer, 1/4-1/2 inch, of slightly mineralized top soil and river gravel on top. My hills have eroded, plants decided to spend most of the year rooting themselves to the bottom of the tank through a few inches of inorganic material in some places and have finally taken off to become a sprawling jungle I need to trim all the time.

My tap water is really hard so I had to use mostly RO and I end up having to do a few water changes here and there with pure RO because the carbonate hardness jumps to 10 dkh rather rather than being taken up by the plants for some reason. I always had a minor iron deficiency which I dosed a small amount of chelated iron for a couple times a week, but now they seem deficient in more nutrients in some areas. I only have a couple mollies and a ton of snails atm so the bio load isn't much.

I never had a lot of algae in the beginning except greasy diatoms and this brown goo that clogs the filter. I do get the mulm that flies all around every time I trim or rinse the sponge protecting pump intake from snails. I was thinking of making a wall of coconut coir the java ferns that don't like to stay put and filter floss to catch the floaty bits that cover the plants.

I am not sure if the substrate is worn out or if the water hardness is blocking nutrient up take. My bacopa carolinia is doing great but swords and hygros look sickly. If I ever do another npt in a hard water area, I will have tie all the plants to coir, place on top of soil, add heavier rocks to keep in place, then put chichlids in with them.


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## Michael (Jul 20, 2010)

My oldest Walstad tank has been set up just over 4 years. It perks along with little attention from me--monthly trimming, the occasional partial water change, cleaning the filter every few months whether it needs it or not. Some of my smaller, younger soil tanks did develop signs of potassium deficiency, so I dose the old one a few times a month with KCl when I do the others.


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## mik778866 (Nov 13, 2014)

Jeffersuan said:


> So the main question: What is a reasonable lifespan to expect out of a NPT before plants stop growing?
> Related question: How can we increase the longevity of our NPTs?
> 
> Thanks!


 Hi @Jeffersuan. Did you figure a method to improve the lifespan of your tank?


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## LittleTinGod (Sep 15, 2015)

In this video:

Interview with Diana Walstad, Author of Ecology of the Planted Aquarium





Diana talks about this quiet a bit at one point. Basically talking about how overtime the tank might evolve from lower tech towards higher tech, but I think as you guys have pointed out there are things you can do to keep it as low tech as possible for a very long time.

One question I have is this: Because I mixed my MGOC with Safe T Sorb that should extend my tank life some because of the STS's ability to absorb nutrients and store them right?


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## f1ea (Jul 7, 2009)

Nice interview.

She mentions CO2 is the #1 issue. That's why i always added at least DIY CO2 to my natural tanks; that way i could keep almost any plant. They were still organic tanks 

Turns out it also adds longevity..... so might as well add it from the beginning if you want a more or less aquascape natural tank. Or go with the robust plants that don't need CO2 surplus...

In terms of soil and nutrients, i find Natural tanks have great longevity. Aquasoil will be depleted in less than a yr. a natural soil tank can go for a few yrs (3+) with no problems.

Edit: oh and to add... Echinodorus and Crypts grew like mad in my soil tanks. Huge, healthy and tons of runners. On aquasoil they grow much more controlled and to a limit... which ironically, i kind of prefer; because those plants became hardscape on my soil tanks. Moving them was sort of like a nuclear holocaust. But looking at them was rewarding... so healthy.


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## Michael (Jul 20, 2010)

Yes, thanks for posting the link.

On CO2, she observes that fast growing and more difficult species flourish in new Walstad tanks, but decline over time while slower growing, more robust species become dominant. That is exactly what I observe in my own tanks--now I have an explanation for it.


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## mik778866 (Nov 13, 2014)

f1ea said:


> She mentions CO2 is the #1 issue. That's why i always added at least DIY CO2 to my natural tanks; that way i could keep almost any plant. They were still organic tanks .


In a NPT, we do little to no water changes. Will this change by supplementing with the DIY CO2?


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## f1ea (Jul 7, 2009)

mik778866 said:


> In a NPT, we do little to no water changes. Will this change by supplementing with the DIY CO2?


Not really. The CO2 is a relatively constant input and doesn't change much in terms of what's in the water, except letting some uncompetitive plants have some C available to grow better.

If you add too much light and start getting more hyper-growth.... then have to dose etc, THEN you'd need to keep up the WC to keep your water chemistry in check (either to replenish some nutrients or to reset some excess from dosing). But if you rely mostly on fish load, and you're not going for 'extraordinary' plant growth, water changes can still remain to almost nothing at all.

Basically, as long as you don't have too much light, you will not be going too far off a normal Natural tank scheme. With the added CO2 you will just have the option to keep simple/robust growing plants PLUS some weaker ones, vs just the robust ones you have to stick with if you don't have extra CO2.


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