Can using C02 control algae

[rickrollxx]

My 46g has been established for months now and grows very well for the most part. I use eco complete with dry fertilizers and also liquid ferts dosing. Also use flourish excel. A lot of my plants have algae on them. I'm at the point now we're I think I'm going to get injected C02 for better plant health. Does anyone have any input on this.

 

[Delapool]

Mainly green-spot algae?


I would say yes (indirectly). Removes one variable to experiment on and plants will be healthier.


I just find it easier - ferts (particularly potassium) in excess although I'm still low dosing on micros at moment (could be my tap water though). Injected CO2 as well. Then only really worrying about light intensity / duration (+ maybe substrate) + if the plants like the water chemistry (mine is a little high in salt) in the first place.


Ime it won't solve algae though. I've had BBA and GSA growing quite happily on the CO2 outlets. And CO2 dosing should be consistent with good flow to spread it around (harder to do in large tanks).


The flip side would be to reduce light / perhaps better light spectrum. Some thoughts.

 

[Fresh2o]

What kind of lighting are you using?
Algae looks to be primarily GSA along with some brown fuzz. The GSA often appears with poor plant growth and insufficient phosphate.
Any idea what the nitrate and phosphate levels are?
Why both dry and liquid ferts? Dry should be sufficient. Are you following the EI or PPS-Pro method?
CO2 does not necessarily control algae directly; rather it helps drive plant growth which outcompetes algae.

 

[rickrollxx]

I am using fluval plant pro lighting. It's on for about 8 hours per day. Nitrate levels are very low and don't know phosphate. I dose liquid ferts about 2-3 times per week and perform weekly water changes. I have even dimmed the lights a little.

 

[rickrollxx]

I have noticed on new growth, there is no algae until growth slows.

 

[kashif314]

Well Seachem excel did help to fight algae. It was not meant to kill algae as it is liquid carbon but many people use it to counter algae successfully. I suggest to stop any fertz u using for a week or more and see if that helps. If it does then reduce the quantity of fertz. I am new to planted tanks but I know sometimes fertz can create problems.

I don't think pressurized co2 can solve algae problem really. But again I am no expert.

 

[Funken_A]

the golden triangle. Light intensity / CO2 / Fertlizers

If any one of those is lacking or if there is too much of any one of those items some sort of algae will form



Your light might be too intense. (Intense light means more energy for photosynthesis which means the plants are sucking up all the nutrients they can find which could possibly represent a deficiency like phosphates which is sometimes linked to green spot alage) Easiest thing to try IMO is to move the light up a few inches, or dim it a little.

Adding CO2 injection is never a bad thing. But like anything it comes with its own challenges and adjusting periods. Its not going to cure your algae problems if the light is too intense or your lacking in a nutrient....

I use CO2 injection as well as liquid Co2. My theory is to provide plenty of Carbon for my plants and make adjustments to my light intensity and nutrient regimen to find that balance. Excess Carbon is not going to cause algae, but way way to much CO2 could gas your fish.. My tank runs above the 30ppm set point many discuss without issue, but you don't want to turn the dial up to un- necessary amounts either..

 

[Bert2oo1]

Funkens nailed it. Co2 just increases the nutrient uptake of plants making them healthier (if the nutrients are avaliable) cause rapid growth and starves the algae of nutrients. If the algae can’t feed due to the plants taking all the goodness then the algae will die.

If lighting is too strong and co2 is pumping in and the nutrients are there then plants will begin to struggle and algae will take over.

The hardest thing with planted tanks is finding what works for your tank. Once you find it, it’s smooth sailing from there.

I’d start by having a lighting period of no more than 8 hours and also lowering the intensity of your lighting if you can [emoji106]

 

[rickrollxx]

I will stop liquid ferts for now and I dimmed lights a little more. I already have the at about 7.5 hours a day. I'll keep tabs on it and go from there. Love the planted tank style and am hooked. Thanks guys for the tips.

 

[Fresh2o]

Why are you stopping the fertilizers? i would address the lighting and leave the ferts and carbon as is. Excess nutrients will be removed during water changes.

 

[rickrollxx]

What about the substrate ferts. Will that add to the water column? I do water changes every week.

 

[Fresh2o]

I️ suppose some substrate fertilizers leach into the water column. Would not be too concerned about it.

 

[Delapool]

I’ve run tests and substrate ferts will leach from gravel (our ‘long life’ ferts from garden section of hardware may not allow for aquarium people using them though). So that’s why suggestion will be to plant substrate ferts tabs as deep as possible. Not huge readings though.

You could either dose following a scheme like EI / PPS-pro with water changes and/or water testing. I test nitrates and phosphates every month roughly to track trends (eg from plant growth vs residual ferts left in water).

I wouldn’t stop ferts dosing. IMO that won’t stop algae growth.

 

[rickrollxx]

Ok. Thanks. A lot more to learn with this. I guess I'll just see what works. Do I want higher phosphates? Not sure on that and why.

 

[PerfectDepth]

I think aquatic plants uptake very little from the substrate, even so-called "heavy root feeders". I think the nutrients surrounding the roots are used mainly for just that: growing roots to anchor the plant. It wouldn't make sense for an aquatic plant to waste energy transporting nutrients from the roots up to the leaves because the leaves themselves can just take in all required nutrients from the water column directly at the site of growth. It shouldn't matter much at all whether the nutrients in the water are from the substrate leaching or from adding fertilizer directly to the water. I stopped adding root tabs to the substrate in my tanks a while back and still have had no trouble growing crypts etc.

 

[Caliban07]

It makes sense that certain aquatic plants would be better adapted to root uptake since many of the species we keep are actually semi aquatic and would only spend a limited amount of time with the leaves submerged.

Root uptake is a three fold mechanism. Mass flow of nutrients, root interception and diffusion. It’s inevitable that plants will uptake from both locations but how much from where could depend on a very large number of factors.

I think it’s better to have nutrients at both sites (more margin for error) but it’s definitely proven that nutrients can be taken up sufficiently from leaves. There would be no reason to alter the structure of the leaves if this was not the case.

 

[PerfectDepth]

I don't know for sure. Transport of nutrients to the site of growth uses up a lot of the energy (from light) that could be used for actual growth instead. It's inefficient, which is why I tend to think submerged aquatic plants would not waste energy transporting nutrients except when/where they are truly needed- while a plant is still transitioning from emmersed into submerged form for example

 

[Caliban07]

It’s a viable hypothesis but we cannot be certain. I think a lot will depend on the nutrient and the species in question.

Very soluble elements like potassium or nitrate will most likely end up in the water column even if you add them to the substrate whereas elements with insoluble oxides or hydroxides like Fe and po4 will become more available in anaerobic zones within the substrate at acidic pH levels.

This information is mostly applicable to terrestrial soils so again it’s very difficult to quantify with any degree of certainty. Experimentation is the Key.

Either way, in my humble opinion o2 is king and good o2 production in a planted tank is the result of photosynthesis which is a function of co2 uptake.

Oxygen also enhances microbial activity which removes harmful nitrogen compounds reducing the chance for algae to gain a foothold.

The most robust aquariums with low algae species make use of both plant mass and microbes.

So yes, co2 can be used to control algae, yet in a rather long winded and miraculous way.

 

[PerfectDepth]

Yeah I get the best results overall when o2 is plentiful. Better growth and less algae. However it does seem that even with plants contributing o2, the rate of gas exchange at the surface is still important. I think many people try to reach a sufficient co2 concentration by trapping co2 in the water just to be conservative, when really it's probably a better practice to "waste" co2 by increasing surface agitation and also increasing co2 output to compensate.

Plenty of healthy, fast-growing plant mass is what will help control algae, and co2 is just a means to achieve this. Co2 does not do anything all on its own other than help algae grow . Algae needs carbon too.

Also very helpful in controlling algae growth are large, frequent water changes to remove dissolved organic material

 

[rickrollxx]

Thank you. All of this is extremely uninformative.