# Balance of light + CO2 + fert



## marcio (Jan 18, 2011)

As algae continue to thrive on my tank - plants seems to be doing OK too, but it feels it will be a matter of time for algae overrun - I can go and remove a lot of what's out there, but the key issue for long-term success is how to balance light + CO2 + ferts (nitrates, phospates, etc). That's where I need some structured guidance. 

I know now I will have to change my 12h/day lighting, low C02, super-low nitrate environ in order to obtain sustainable algae control. The question is: what to do? Less light, more CO2 and what ferts.

I am sure this has been discussed a thousand times before and I found all this threads with conflicting information... could you point me to either a good APC thread on the subject or an authoritative online source (to the extent that such a source exist)?

Thanks!


----------



## wwh2694 (Aug 15, 2008)

You need to lower ur lighting to 8-10hrs a day. U need a drop checker for ur CO2 make sure its on the lime green side make sure is on 1hr before lights comes on. Fertz do use EI or pps pro? Either one is great. I use pps pro with auto dosing. U need consistent dosing for the plants to trive. Once everything is balance u will see ur plants pearl.


----------



## alexopolus (Jan 18, 2010)

I agree with wwh2694. 
Why dont you try a black out?(2-3 days lights off) after that jus lower your lighting to 8hr and start with fertz. You can do EI or PPS (love this last one, because you dont have to do 50%water change every weeekend, EI gets anoying after a while). PPS-PRO works for me, if you want i can give you some fertz so you can try it (next sunday meeting).

I believe this + all the changes that you have allready done (more water flow) will take care of your problem.

Here is the a PPS link
http://www.aquaticplantcentral.com/...etual-preservation-systems-aquatic-plant.html


----------



## marcio (Jan 18, 2011)

Thanks, Alex!

I will take your offer on getting started on the ferts... thanks for the support and advice! I will start the black-out tonight and by Sunday I will have something to report. My tank is super-low on nitrates and phosphates... I assume that's what the ferts are about.

Regarding CO2 + light, I found this interesting article from tropica. I guess it's authoritative?! Of special interest is the chart that shows the curves of biomass growth under the combinations of CO2 + light... growth under high CO2 + high light is exponentially faster than all other scenarios. I guess I will strive to be somewhere between the two higher curves...

http://www.tropica.com/advising/technical-articles/biology-of-aquatic-plants/co2-and-light.aspx


----------



## H2OAggie (Jan 10, 2011)

I have a new (3 month or so) planted aquarium where I am also having trouble balancing everything. I began EI dosing before I started DIY CO2 and had a 12 hr photo period, which helped lead to BBA and GSA. Even the DIY CO2 is too inconsistent, so I have ordered the parts for pressurized CO2. Hopefully with that addition, reducing the photo period to 8 hrs, and treating the BBA with H2O2 I can get the tank back in sync.


----------



## Ekrindul (Jul 3, 2010)

alexopolus said:


> You can do EI or PPS (love this last one, because you dont have to do 50%water change every weeekend, EI gets anoying after a while).


Water changes are not a requirement with EI. Never have been, never were. It's a misconception. They are suggested if you don't want to have to do any tweaking or worry about having enough fertilizer. EI can be done without frequent water changes, however. Tom Barr explains in this thread (see Plantbrain post): http://www.plantedtank.net/forums/g...cussion/108616-ei-dosing-water-changes-2.html

PPS Pro seeks to apply the minimum amount of fertilizer necessary and tweak as deficiencies appear. EI applies a known amount of fertilizer from the beginning that is non-limiting, and from there, the aquarist can lower dosing until the plants show decline in health. Once this level is reached, water changes can be reduced, and even discontinued, since the level of uptake is known.

Each method can achieve roughly the same thing. I personally prefer EI for various reasons, but I think PPS Pro is perfectly viable.


----------



## marcio (Jan 18, 2011)

Thanks for the engaging discussion and the link!

OK, a basic question: what is the role of ferts as "algae prevention" tool? I understand dosage of PO4 would repress certain types and keeping nitrates are a certain level would work on others?
Thanks!


----------



## Ekrindul (Jul 3, 2010)

I believe that healthy plants prevent algae. If you focus on what makes plants healthy, you won't have to worry about algae.

So, you have to ask, is a limitation in a plant's best interest? 

I won't try to talk about PO4 and carbon uptake, as I simply don't understand the science, but I will suggest you look into that if you are interested in understanding the relationship. Carbon deficiency seems to lead to alot of algae issues. Since light and carbon drive plant growth, which drives nutrient uptake, if you were an algae looking for a window to compete with plants, what would you watch out for? I would watch out for carbon fluctuation.


----------



## marcio (Jan 18, 2011)

Ekrindul said:


> Since light and carbon drive plant growth, which drives nutrient uptake, if you were an algae looking for a window to compete with plants, what would you watch out for? I would watch out for carbon fluctuation.


So a strategy to prevent algae would be: make sure CO2 is set at a certain level via pressurized at, say 30 ppm - so little CO2 fluctuation, no algae bloom... having that out of the way, work with the levers of light and ferts to manage plant growth.

Does it sound right? And if so... how do non-CO2 tanks cope with algae? It seems to be that, unless there are certain level of macros HIGH enough to inhibit algae, if there are nutrients for plants, the algae can eat it too, so the key is that plant growth prevent the algae from going into active stage (rather than spores) to start with.


----------



## Ekrindul (Jul 3, 2010)

I wouldn't try to aim for a ppm level. The reason a ppm level is not a good measure is it can depend on many factors: light level, plant mass, circulation, even O2 level (you actually want a good O2 level as well as a good CO2 level despite common advice). As the plant mass increases, CO2 demand will increase. As light increases, CO2 demand will increase. Poor circulation, even with a high CO2 level, can lead to poor uptake in parts of the aquarium. So, a ppm level isn't a good measure. Depending on the factors in your tank, 30ppm may be way more than you need, or not enough.

Your measure of how much is right should first be the fish, plants second. So, adjustment should be done slowly with a period of observation over several days in between each change. The first day, obviously, you watch the fish. If the fish show stress, then back off and focus on circulating the CO2 as efficiently as possible.If they show no stress, watch for improvement in the plants. If you don't like the results, increase slightly and start over.

Non-CO2 tanks can avoid algae by using less light, first of all. Secondly, fewer or no water changes (only top off for evaporation) will help keep CO2 levels consistent. Less CO2/light means slower growth, less nutrient demand. So you can dose much less, too. Algae doesn't like low light or consistent CO2.

Nutrients themselves will not prevent algae. It is always an indirect relationship. Obviously, you can't dump nutrients in a fish-only tank and prevent algae. The opposite would occur most likely. So don't think of it that way. It's not nutrients preventing algae; it's plants not suffering from nutrient deficiency.

NH4 and inconsistent CO2 seem to be the most commonly observed triggers. Plants use up NH4, so algae looks for it in the water column. An environment with alot of spare NH4 probably won't have alot of competing plants, right? An environment with unstable CO2 will probably have plants that are in a weakened state, since they are either running out of CO2 or focusing their energy in trying to uptake CO2 from various sources to make up for the frequent loss of it in the form of dissolved CO2, which is easy for the plants to uptake. In other forms, carbon requires some less efficient chemistry in the form of enzymes the plant must build. Once the dissolved carbon returns, it destroys the enzymes. Wasteful! This is why in a non-CO2 tank, it's best to avoid water changes. It conditions the plants to keep those enzymes and uptake carbon from those less efficient sources _all the time_.

Think of it this way: When you introduce plants to a large volume of CO2, they have no way of knowing it is only temporary. They build based on the level you give them until they run out of something they need. Then they are stuck with what they've built. If they cannot maintain it, they decline.


----------



## Ekrindul (Jul 3, 2010)

Also, I would say finding the right level of light is more important than anything else. Finding a good, safe level of CO2 becomes much easier with lower light.


----------



## MacFan (Jul 30, 2006)

In theory, if you dose ferts in the right ratios, you can dose them higher than the plants require and then the plants will grow like crazy and out-compete the algae for those resources. In careful testing by Tom Barr and others, excess nutrients does not cause algae assuming all other conditions are correct. That said, it's easy to have low CO2, poor circulation, etc. so algae is possible, but it's generally a sign that something is out of balance. (BBA I'm not convinced though.)

The goal of EI is to dose just above what the plants need, but still at the appropriate ratios. Because consumer grade test kits are not very accurate and testing is a pain, it's also based on following a regimen of dosing that should achieve a specific level before the plants consume it. Since we don't know what the plants actually consume without testing, and we don't want to test, we do a 50% weekly water change to reset the levels to half what they were. That prevents any one thing from getting out of control. For example, if our plants are consuming as much phosphates as we're adding, then each time we dose, it gets higher and higher until it becomes out of balance with the nitrates and algae breaks out. But the weekly water change cuts that level in half so it can never get above a certain level and thus remain in control. 

Like many things, it's easy to understand and recite... harder to actually do in practice! I've been reading the last few days and realizing that I need to revisit my dosing as it's not right. The deficiencies thread someone posted shows that my plants are having some of those symptoms. So while I generally avoid algae (except BBA), I suspect my plants are consuming all the phosphates before the nitrates. But I can't just increase phosphates without a corresponding increase to nitrates or they will be out of balance. So I'll increase both once I dig out some CO2 indicators and confirm I'm getting good CO2 levels. 

Michael


----------



## Phil Edwards (Jan 22, 2004)

Maricio,

What a good question! I'm sure you've already found that the answers will vary depending on who's answering the question. We all have our own ideas and experiences which have given us success or failure. 

In my experience and through the testing I've done I believe the presence of ammonia (NH3-) and ammonium (NH4+) along with insufficient carbon levels trigger algal growth. In backyard tests I found that urea and ammonia based fertilizers cause algae to grow much faster than nitrate based fertilization under identical light and carbon regimes. Addition of carbon as CO2 gas enhanced plant growth with corresponding reduction in visible algae, even with the continued use of urea and ammonia based fertilizers. Even so, algae were still present in what I consider to be nuisance levels with those fertilizers and CO2 enrichment. This leads me to believe that a temporary spike in NHx compounds along with reduced carbon availability benefits the germination and growth of algae to nuisance levels. 

Based on the scientific papers I've read ammonium is one of the preferred forms of nitrogen for plants. Nitrate is slightly harder to metabolize, but is available in much greater quantity than ammonium in nearly every aquatic system. Plants have adapted different mechanisms for metabolizing both compounds, which is why we're able to use nitrate (NO3-) with such success in our aquaria.

Back to light and CO2. Think of your aquarium as an organism with light as the metabolism and CO2 as the lungs. As your metabolic rate increases your lungs needs to take in increasing amounts of oxygen to fuel your metabolic needs. In a planted aquarium, increasing light increases plant metabolism which requires a corresponding increase in carbon. If the plant isn't able to get carbon from the water in the form of dissolved inorganic carbon (CO2 gas) or alkalinity (Carbonate) it will start using up its own carbon reserves (starches and other carbohydrates) to fuel new growth. Once those stores are depleted the plant is carbon limited and will be unable to take up nitrogen, phosphorus, etc from the water as efficiently as it did before. This reduced uptake and release of organic byproducts creates an imbalance in the metabolism of the aquarium. This is when we start to see algae growing. 

Similar conditions can be found in systems with a high bioload and/or fresh organic rich substrates like Aquasoil. This initial and uncontrolled release of nutrients into the water column when plants aren't established yet or are unhealthy and are unable to take up these nutrients is a prime cause of algal growth in new aquaria. Uncontrolled nutrient levels in aquaria with high bioloads and insufficient light and carbon supplies are another cause of algal growth. 

What does that mean for your tank and how you can best manage it? Assuming you're not willing to reduce bioload you first need to get your light and carbon inputs in balance. The good news is this is easily done! Set your lights to be on for 10 hours a day and don't change it. Over the next couple days begin increasing your CO2 up to 30ppm. (Yes, I'm an advocate for higher CO2 levels when trying to remedy nuisance algae) Once your photoperiod and CO2 input are stablized do a massive water change (50-75%) and clean the hell out of your substrate. Doing this has accomplished two important things; you've set a regular carbon level at a point which is not limiting to your plants, and you've removed a source of uncontrolled nutrient input. Immediately after your water change start dosing fertilizers as described in the original EI method. We might not all agree with what Tom has to say, but the levels in the EI method are based off critical nutrient levels found in reputable scientific papers and they're a good foundation to start with. 

Follow the EI dosing, maintain your CO2 and light levels, do your regular water changes, and observe your aquarium over the next three months. Don't change your fertilization or maintenance routine in this time; just observe and trim as needed. After these three months of careful and regular observation you should have a good idea of the metabolism of your aquarium and can begin changing things as you feel you need. 

There's nothing at all wrong with "painting by numbers" when learning all this. The less you have to think about specific nutrient levels the more time you have to concentrate on learning how your plants and fish grow and what they look like when healthy. As soon as you know what they're supposed to look like you'll spot signs of stress right away and will be able to fix them before the problem gets out of hand. I've used EI and a modified EI method in my tanks for years and years with great success. Whenever I encounter an issue in someone's tank or start up a new tank of my own I invariably fall back to the fundamentals of EI (even in tanks with a soil based substrate) until I've got a good grip on that particular system. Once I have a good idea how the tank will respond then I get into messing with nutrient levels and changing over to something more akin to PPS.

Cheers,
Phil


----------



## Phil Edwards (Jan 22, 2004)

MacFan said:


> But I can't just increase phosphates without a corresponding increase to nitrates or they will be out of balance. So I'll increase both once I dig out some CO2 indicators and confirm I'm getting good CO2 levels.
> 
> Michael


Yes you can! The idea behind maintaining nutrient ratios applies to the water column, not to the plants themselves. Plants will store excesses of nutrients in different ratios; I've seen this in my own research. As long as nutrients don't become limiting at the supply end the plants and water changes will do the rest. If your plants are taking up all of the phosphate in the water before you dose again, increase your P supplimentation; the plants clearly can use more.

Of all nutrients, I've found my plants have consistently responded the best and fastest to P supplimentation. In tanks where pearling has been heavy if I notice a reduction in pearling the addition of P has brought it back up to normal levels within an hour or two. The first part of photosynthesis is heavy in phosphate bearing molecules (ATP and NADPH), if P is lacking then the reaction becomes rate limited.

Moral of the story? Don't be afraid to add more P without a corresponding increase in N, just try a quarter or half dose. :cheer2:


----------



## bosmahe1 (May 14, 2005)

I am currently using EI but would like to try PPS Pro. I have a 46 BF aquarium with pressurized Co2 with yellow green 4dkh drop checker. I run one 39 watt T5ho bulb and solenoid on a timer that starts two hours before a second timer turns on a second 39 watt bulb. The two bulbs run for 5 hours then this is followed by the first bulb running for an additional hour. In other words, 8 hour light cycle with both bulbs running for 5 hours.

My question is, should I start with the dosage recommended with this calculator, or should I start with something richer?

http://sites.google.com/site/aquaticplantfertilizer/home/pps-pro

Am I understanding it correctly that I should use 5 ml doses for 50 gallons of water? Off hand, this seems too lean to me. Any guidance would be appreciated.


----------



## marcio (Jan 18, 2011)

Phil Edwards said:


> Maricio,
> 
> What a good question! I'm sure you've already found that the answers will vary depending on who's answering the question. We all have our own ideas and experiences which have given us success or failure.
> 
> ...


Thanks Phil for the time and attention for such a detailed post. That's the type of analytical stuff I like about the hobby! I am out of town for a few days but will review in detail what you wrote and catch-up with APC next week.


----------



## fishyjoe24 (May 18, 2010)

this is a interesting read, I had medium light and put another t5 no 2 bulb fixture over the tank, for the glosso but now I have brown spot algae... I was also uping the ferts a little bit... now did I get the algae do to more ferts and light?


----------

