CO2 in betta tank w/ Air based filter

[kstringer1974]

I have a little 2.5G betta tank in my oldest daughter's room. Since I like plants so much, I thought I would put in some low light species and have a mini-planted tank, as I've always felt a planted tank looks better than just about any other kind of tank out there.

Anyhow, the tank originally had a whisper 10i HOB filter, but the current it created was just too much for the betta, who had to constantly fight the current even when at rest. So I switched to an air pump powered unit that seemed relatively new to me. It pumps air from the pump through a foam block and activated carbon unit.

Obviously this would increase the gas exchange significantly due to the constant disturbance of the water's surface. I inject CO2 into the tank currently as my belief is that CO2 levels would never be sufficient in the tank with this kind of filter as CO2 would be lost in the increased gas exchange. Is this thinking correct? Should I move away from this type of filter entirely and go to something else? If so, what are some suggestions?

I have constant issues with filamentous algae in this tank, which I dilligently scrub off every week during the tank's water change. Is there something that I'm missing that could be causing this in a low light tank?

Tank specs:
Lighting: 10W screw in CF 50/50 Max bulb (I forget the manufacturer, but you can find this bulb in just about any fish store)
Substrate: Eco-complete
Water changes - 50% weekly
Occupants: Cryptocoryne wendii, java moss, java fern. The Java fern and java moss are attached to pieces of driftwood. Princess Sarah, the crown tailed betta (so named because my daughter refused to believe that such a pretty fish could be a male)
Ferts: prepackaged stuff that I have used in other tanks. Concentrations are hard to judge though for this tank because of it's tiny size...hence the large water changes.
Ammonia and Nitrite levels are a constant zero. Nitrate is always 5ppm or less when I bother to test it.
Out of the tap, I get the following measurements:
PH: fluctuates between 7.6 and 8.0
GH: fluctuates but is generally around 5-7ppm
KH: pretty constant at 4 degrees

Thank you,

 

[ceg4048]

Hi Kevin,
There are a couple of items in your post which seem a bit conflictive so perhaps if we can clarify it might enable us to zero in. You are certainly correct in that bubbles that break the surface will drive off the CO2 you are injecting, so if you want to maintain a certain level of CO2 bubbles are counterproductive. It might be better to use one of the low power internal filters like the Rena Filstar 1 or the Hagen Fluval 1. These have directional outflow spuds so that you can point the flow against the glass say, or you can connext tubing to the spud and port the flow through a spraybar.

Next is the issue of your fertilization. You refer to it as "prepackaged stuff used in other tanks". Inquiring planted tank minds always want to know what's in it. We need to determine the Nitrogen, Phosphorous and Potassium content as well as thetrace element content otherwise you have no way of knowing whether the plants are being fed correctly. Your filamentous algae may be either the result of poor nutrient levels or of inconsistent CO2. It looks like your tap water is really soft so you may develop issues with mineral deficiencies (such as calcium and magnesium) if not addressed.

There is another inconsistency; your assertion that ammonia and nitrite are zero. This is never true as ammonia is always being produced and either being absorbed by plants, reduce by bacteria or utilized by algae. The fact that your test kit reads zero merely means that the reagents in the kit are not able to measure below a certain level.

You should check the posts in the EI section to see the differences in techniques for high tech methods versus low tech methods. The two techniques are diametrically opposed so that you should do one or the other not both. If you are doing the low light/low tech then you should delete CO2 addition and minimize the water changes.

Whichever method you use though you should dose appropriately and you should be aware of what types of nutrients and what quantities are being dosed.

Cheers,

 

[FacePlanted]

Again, well put ceg4048. I always love reading your posts. They are always so clear and articulate.

I second what ceg4048 says in the previous post. Do one or the other methods, but a mix of both won't really work. Read the stickies in the EI forum. They will outline the high tech vs. low tech methods.

-Mike B-

 

[kstringer1974]

First off, let me say thank you for you response. I genuinely do appreciate it. Let me see if I can clear up some of the questions and then I need to add some of my own.

With the CO2 injection, I have the bubbles through a microbubbler under a cone shaped piece of driftwood with java moss stuffed in the narrower top end. My idea was that this would allow more CO2 to go to it's aqueous form rather than be lost as a gas at the top of the tank. My understanding from other articles I've read (I believe it was on this site too) is that any addition of CO2, even in low light tanks has a significant positive effect on plant growth. However, I do agree that the air driven filter is a poor choice here if I want to have plants in this small tank and use CO2 injection.

The off the shelf fertilizer was Pond Flourish. I would add one drop twice a week because the concentrations were for a pond and certainly not a super small 2.5G tank. After I posted, I dug around and found my PMDD CSM+B pre-mix which I started using instead. However, after further research, I've learned that this lacks sufficent levels of K and that I need to dose K separately/additionally in order to provide the correct level of that nutrient in balance with everything else.

You make a good point about the water being particularly soft. I hadn't really thought about that for this tank but I will give a try to adding additional calcium and magnesium. Do you, or anyone else from this site, have suggestions on good ways to add these nutrients? I'm guessing I should probably just buy the specific nurtients in dry bulk from a site such as GregWatson.com but I'm certainly open to suggestions.

In regards to my assertion regarding the NH3 and NO2 levels, you are correct, I am going by my test kit. However, I'm not sure how that comes into play except as semantics. If the levels are below what my test kit can measure (SeaLabs test kits) wouldn't that indicate that these chemicals are not at issue? I say zero because that is all I can go by.

I would be very interested to hear success stories and methodologies for other people with nano (as in under 10 gallons) planted tanks. I'm working on a 30G planted tank that is coming along nicely as a high tech/high light environment but I do not have the knowledge nor the desire to try and do this to my daughter's betta tank.

Again, thank you for your feedback. I love this site for people such as yourself who are knowledgable and never make those of us who are still stumbling along the path feel stupid.

Cheers,
Kevin

Hi Kevin,
There are a couple of items in your post which seem a bit conflictive so perhaps if we can clarify it might enable us to zero in. You are certainly correct in that bubbles that break the surface will drive off the CO2 you are injecting, so if you want to maintain a certain level of CO2 bubbles are counterproductive. It might be better to use one of the low power internal filters like the Rena Filstar 1 or the Hagen Fluval 1. These have directional outflow spuds so that you can point the flow against the glass say, or you can connext tubing to the spud and port the flow through a spraybar.

Next is the issue of your fertilization. You refer to it as "prepackaged stuff used in other tanks". Inquiring planted tank minds always want to know what's in it. We need to determine the Nitrogen, Phosphorous and Potassium content as well as thetrace element content otherwise you have no way of knowing whether the plants are being fed correctly. Your filamentous algae may be either the result of poor nutrient levels or of inconsistent CO2. It looks like your tap water is really soft so you may develop issues with mineral deficiencies (such as calcium and magnesium) if not addressed.

There is another inconsistency; your assertion that ammonia and nitrite are zero. This is never true as ammonia is always being produced and either being absorbed by plants, reduce by bacteria or utilized by algae. The fact that your test kit reads zero merely means that the reagents in the kit are not able to measure below a certain level.

You should check the posts in the EI section to see the differences in techniques for high tech methods versus low tech methods. The two techniques are diametrically opposed so that you should do one or the other not both. If you are doing the low light/low tech then you should delete CO2 addition and minimize the water changes.

Whichever method you use though you should dose appropriately and you should be aware of what types of nutrients and what quantities are being dosed.

Cheers,

 

[Carissa]

I use co2 in my low light tank (currently 1.25 watts/gallon) and it always makes things grow nicer. However, unstable levels of co2 are worse than stable, low levels, when it comes to fighting algae. You mentioned that your pH is fluctuating, this may be due to unstable co2. If this is the case you probably need to address this problem, whether it be by fixing your setup, or removing co2 altogether.

Personally I have found that you want as little light as you can get away with. Since all your plants are very low light, you could try cutting back your lighting a bit and see how the algae and plants respond. I have successfully grown java ferns under incandescent lighting before so I know they can handle it, but you can watch and see what happens. I know the watts per gallon thing doesn't hold up in nano tanks but it might be worth a shot to reduce a bit.

If you really want to do things right you could get the dry powder fertilizers individually, then you would know exactly how much to add of each nutrient to bring levels to a certain ppm each week, eliminate the guesswork and know that you are adding enough of everything and deficiency therefore isn't a problem.

Epsom salts will add magnesium, calcium chloride (sold as pool hardness increaser) will add calcium. Or get GH builder, which will accomplish the same thing.

Just a little clarification on the CO2 issue. It sounds like you are saying that you think that increased circulation in a non-co2 tank will drive off co2. Actually, increased circulation in a non-co2 tank will usually increase the amount of co2 available to the plants, because the plants will be using up what little co2 there is in the water, and without sufficient circulation the water won't be able to reabsorb more co2 from the surface. Equilibrium is the highest co2 level we can aspire to in a tank with no injection. But on the other hand, in a co2 injected tank, we are not trying to achieve equilibrium with the atmosphere, we are trying to artificially keep co2 levels higher than equilibrium. In this case circulating the water to the surface will just cause the tank to lose co2 faster, equilibrium becomes the enemy.

 

[ceg4048]

Hi Kevin,
OK, I've had a look at this product called "Pond Flourish" at Dr. foster & Smith website is this the product? Pond Plant Nutrition & Health: Pond Flourish

If so then this is just a trace element mix and actually replicates the CSM+B (and holy cow it looks like it's about 100X the price of CSM+B!)

I reckon a single betta cannot produce enough nitrate and phosphate to satisfy you plants. This could easily be one of the factors leading to the filamentous algae you mentioned in your first post in which you asked if you were missing something. I would say you are definitively missing N P and K. I believe the same site that you purchased the CSM (gregwatson.com) ought to sell the KNO3 (potassium nitrate) and KH2PO4 (potassium phosphate). You don't need a whole lot of these with such a small tank but you do need them as they are fundamental (and cheap).

Since you won't have to be buying Pond Flourish anymore my suggestion is to use the $28.99 savings and buy Flourish Excel instead: Flourish Excel

If you dose this regularly you can completely eliminate the CO2 gas injection as this product provides a non-gaseous form of carbon. The only caution is that there are some plants that respond negatively to Excel such as vallis and liverworts such as riccia. Your crypts, moss and ferns will be fine.

As carissa mentioned, I would just get GH booster. All you would need is a pinch every water change and you're done. That solves the soft water issue immediately.

Finally, regarding your ammonia readings, remember that the purpose of the NH4 kit is to ensure that the ammonia levels are below levels considered toxic to fish and other critters. That's fine, but we are also concerned about the proliferation of algae. It's possible and even likely that in a tank, uneaten food, feces/urine, decayed leaves and unhealthy plants can result in ammonia levels low enough to be undetectable by your kit (zero reading) but that are high enough to trigger algae spores to bloom.

Here is a likely scenario currently being experienced in your tank:

For the amount of light being provided there are insufficient levels of the macronutrients N, P and K as well as possible deficiency of calcium and magnesium. The plants are weakened and jettison ammonia and other products into the water due to breakdown of their cell walls as a result of starvation. Algae spores are awoken by the presence of ammonia, feed on the ammonia and attack the plants, further weakening them.

To resolve this you need to concentrate on getting the plants healthy so that as you halt their decline you will also halt their contributing to the feeding of the algae. You can do this by the following scheme:
Once a week, after every water change add 1/2 gram KNO3, 1/5 gram KH2PO4 and a pinch of GH Booster (the standard dose is 1/8 of a teaspoon per 100L). Also dose the Excel per bottle instructions. That's it. Continue to scrub away the algae and remove dead or dying leaves. Within three weeks the tank ought to be looking 100% better.

Somewhere on this board are instructions to mix the nutrients in water so that you don't have to try to measure ridiculously small quantities like 1/5 gram or 1/64th teaspoon.

Cheers,

 

[kstringer1974]

Thank you, what an excellent reply and extremely useful!

Yeah, the Pond fertilizer was a mistake. I originally bought it in preparation for a pond but the pond project fell through and I hate to waste something. But it's scrapped now and on to a better fertilizing regimine

However, the guaranteed analysis on the stuff reads:

Total N - 0.07% (Water soluble)
Available P2O3 - 0.01%
Soluble K2O - 0.37%
Ca - 0.14%
Mg - 0.11% (water soluble)
S - 0.27773% (Combined Sulfur)
B - 0.0009%
Cl - 1.15%
Cu - 0.0001% (soluble)
Fe - 0.32%
Mn - 0.0118% (soluble)
Mo - 0.0009%
Na - 0.13%
Zn - 0.0007%

So there is NPK in the mix. My presumption is that the concentrations being made for a pond (instructions are for 20mL per 250 US Gallons) are so high that perhaps even a drop or heaven forbid, two drops are just too much of a particular nutrient(s) and trigger an algae bloom. Per your statement of undetectable levels of NH4 being able to trigger algae, I would think that the conjunction of the two things (NH4 and concetrations of certain nutrients) could very well lead to my problem with thread algae.

I use Flourish Excel periodically. I used to use it as the only means of adding carbon to this tank however, I tapered off using it when I started adding CO2 injection.

Also, to Carissa's comments about CO2 in the tank vs. the gas exchange, I am confused by this. Other reading I've done on this subject seems to indicate that carbon in the aqautic environment is not really obtained from the atmosphere in the gas exchange at the surface. It is predominantly created through other means in the water itself which creates the soluble form of carbon that is available to plants. Is that inaccurate? The purpose of adding CO2 injection is to create a plentiful source of carbon for the plants, even if much of goes wasted due to the agitation at the surface.

Lastly, to avoid adding another post, Carissa had made the comment about my PH fluctuations. Those readings are straight out of my tapwater. The fluctuations I image are caused by the fact that the water supply in my area comes from multiple large lakes and the PH may fluctuate there or somewhere along the water supply chain. I am considering purchasing a neutral regulator (PH 7) type product. Is this useful or should I avoid doing so? the PH adjusting product would be for this tiny tank and also for my 30G planted tank as well.

Thank you both for your feedback.

Cheers,
Kevin


Actually

Hi Kevin,
OK, I've had a look at this product called "Pond Flourish" at Dr. foster & Smith website is this the product? Pond Plant Nutrition & Health: Pond Flourish

If so then this is just a trace element mix and actually replicates the CSM+B (and holy cow it looks like it's about 100X the price of CSM+B!)

I reckon a single betta cannot produce enough nitrate and phosphate to satisfy you plants. This could easily be one of the factors leading to the filamentous algae you mentioned in your first post in which you asked if you were missing something. I would say you are definitively missing N P and K. I believe the same site that you purchased the CSM (gregwatson.com) ought to sell the KNO3 (potassium nitrate) and KH2PO4 (potassium phosphate). You don't need a whole lot of these with such a small tank but you do need them as they are fundamental (and cheap).

Since you won't have to be buying Pond Flourish anymore my suggestion is to use the $28.99 savings and buy Flourish Excel instead: Flourish Excel

If you dose this regularly you can completely eliminate the CO2 gas injection as this product provides a non-gaseous form of carbon. The only caution is that there are some plants that respond negatively to Excel such as vallis and liverworts such as riccia. Your crypts, moss and ferns will be fine.

As carissa mentioned, I would just get GH booster. All you would need is a pinch every water change and you're done. That solves the soft water issue immediately.

Finally, regarding your ammonia readings, remember that the purpose of the NH4 kit is to ensure that the ammonia levels are below levels considered toxic to fish and other critters. That's fine, but we are also concerned about the proliferation of algae. It's possible and even likely that in a tank, uneaten food, feces/urine, decayed leaves and unhealthy plants can result in ammonia levels low enough to be undetectable by your kit (zero reading) but that are high enough to trigger algae spores to bloom.

Here is a likely scenario currently being experienced in your tank:

For the amount of light being provided there are insufficient levels of the macronutrients N, P and K as well as possible deficiency of calcium and magnesium. The plants are weakened and jettison ammonia and other products into the water due to breakdown of their cell walls as a result of starvation. Algae spores are awoken by the presence of ammonia, feed on the ammonia and attack the plants, further weakening them.

To resolve this you need to concentrate on getting the plants healthy so that as you halt their decline you will also halt their contributing to the feeding of the algae. You can do this by the following scheme:
Once a week, after every water change add 1/2 gram KNO3, 1/5 gram KH2PO4 and a pinch of GH Booster (the standard dose is 1/8 of a teaspoon per 100L). Also dose the Excel per bottle instructions. That's it. Continue to scrub away the algae and remove dead or dying leaves. Within three weeks the tank ought to be looking 100% better.

Somewhere on this board are instructions to mix the nutrients in water so that you don't have to try to measure ridiculously small quantities like 1/5 gram or 1/64th teaspoon.

Cheers,

 

[VaughnH]

Please, don't use any product to "regulate" the pH. It isn't important to maintain a constant pH, unless you are doing so by injecting CO2 and monitoring the pH to keep the amount of CO2 in the water constant. Almost all plants and fish will do fine with any pH between 5.5 and 7.5. But, adding more stuff dissolved in the water to artificially change the pH cand be harmful to the fish.

Plants in our aquariums get carbon from dissolved CO2 in the water, from gaseous CO2 in bubbles in the water, from carbonates in the water (some plants), from Excel in the water, and, in low light, non Co2 tanks, from natural compounds in the substrate. The more disturbed the water surface is the more likely the water will be at the concentration of CO2 that is in equilibrium with the CO2 in the air above the water. That loses CO2 from the water if we are injecting it, but it adds CO2 to the water if we aren't injecting it.

About the NPK: those are macronutrients, needed in much higher concentrations than the micronutrients that are in any trace element mixture, including your Flourish. They need to be added separately from the trace element mix, or, for low light tanks, they can be obtained from excess fish food and fish poop. Ammonium is a source of nitrogen that plants can use, but it is also a signal to algae to start growing. So, avoiding ammonia is a good idea.