CO2 injection + Betta problem

[SnyperP]

I have been playing around with DIY co2 injection for alittle while. It's in a small 5 gallon tank with just a few plants. I guess the real objective behind that is just to promote plant growth. I apologize for my ignorance, but i have a 13w light that is in the form of a U (no idea what type of lighting it is). Some random fish really: 2 plecos, algae eater, guppers (feeders for the flowerhorn), ghostshrimp, a betta.

The CO2 injection was working great, the plants were growing rather well...but that wasn't the problem. I've been trying to read alot about CO2 injection and alot of people warn about oversaturating the water with it. I monitered the levels quite actively and everything seemed great. One morning I went to feed the fish and i notice my poor betta laying on it's side at the top of the tank. I figured it was dead and went to pick it out, it slightly flopped away. I immediately removed the CO2. I took a look at the other fish and they seemed fine, swimming around. Actually the guppies had torn all the betta's fins away.

It then dawned on me, bettas breathe oxygen from above the water! Some CO2 must have accumulated right about the tank suffocated my poor betta! I tried to give my fish some fresh air, but it was already too late. Has anyone else had this problem in their tank? I'm thinking my yeast/sugar mixture produced too much CO2 and allowed the accumlation of CO2 above the water. If it's not that, is there any other solution to this problem.

Oh. I wanted to move my crowntail betta over to the planted tank. I enjoy how it looks and the old betta seemed pleased with it was well. That's why I'm looking for some solution. I don't want to risk killing this one either.

Thanks for any help!

 

[BrianNY]

Hmmm. Not sure I (or anyone), can confirm your thinking. CO2 should gas out into the room and not be confined to a layer above your tank. Is the tank tightly covered?

 

[TankGirl]

When injecting CO2 it is always wise to measure it, with the KH and pH values of your tap water used in a formula found here:
http://www.csd.net/~cgadd/aqua/art_plant_co2chart.htm

This way you know exactly how much CO2 you are using and the fish won't be in danger. If the plants are growing well then there will be enough O2 so as not to create a problem for your betta, which is what would drive him to the surface (aside from typical bubblenes building).

For a tank this size it is a lot easier to dose Flourish Excel but I have a CO2 injected 5gal so I know where you are coming from! Seems like all I do is prune... quite a fish load you have in there!

 

[hashbaz]

I will second what BrianNY was thinking. While too much CO2 in the water might be a problem, it will not collect above the water (unless very tightly covered). Very few gases will do that sort of thing.

 

[SnyperP]

I remember hear about some natural disasters near volcanos where CO2 is released into a lake. Something (earthqauke) disturbs the water and releases massive amounts of CO2. This then blanketed the near by area (covering a village) and suffocating them all. This happened in africa i believe. From that i just assumed that CO2 is denser than normal air. If it's not possible for it to accumlate, i'm not sure what killed my betta then.

About overstocking, i'm thinking about moving some plants, betta and a plecos to 2 1/2 gallon. I'm looking into getting some flourish instead of CO2 injection. Really depends if they sell it in my area. Looking for some java moss as well. I was considering buying it online, but i can't bring my self to play $15 dollars for shipping something that isn't even half the cost =/

 

[malkore]

No pleco is suited to a 2.5 gallon tank...and frankly 2.5 gallons isn't enough for even 1 betta...5gallons is the minimum tank size for any fish. However this is a plant forum, so let me get back on track.

Talk to your LFS and see if they can order java moss...it's common enough, and a low light plant so they should be able to sell it to other customers if you don't buy all they get (unlike high light plants which would just die in their tanks).

Also, with 13watts over a 5 gallon...its debatable whether CO2's even needed. I'd say if your DIY seemed to help, then keep putting it in, but as TankGirl mentions, you absolutely MUST know your Kh and pH so you can determine CO2 levels.

I'm sorry for your betta...I think they are great fish (I currently have 3). Unfortunately, a lot of the bettas you find are older, and have led a rough life. Its possible it was just his time to go.

 

[Minze]

I have been thinking of moving an African Clawed Frog from it's current 10G tank to a 20G long tank. I have been batting around the idea of making this a planted tank with the frog and a few guppies. No one else has experienced a CO2 buildup inside the tank? This was something that I have not thought of until I read this thread. A CO2 buildup would not be good since they breath air from the top of the tank.

 

[An t-iasg]

I don't use CO2 injection, so I can't really comment on that. I do think, like Malkore suggested, that a 2.5 gallon tank is way too small for a betta (even by himself) and some plecos. Guppies and bettas aren't compatible, and in a small tank, their aggression was multiplied.

I have two bettas, each in their own 5.5 gallon tanks. The tanks are in an L-shape on the counter, and one light hangs diagonally over both tanks. It's a Penn Plax 15-watt light. Each tank has some java moss. One tank has a Cryptocoryne walkerii, and for the other tank, I'm going to get an Anubias barteri nana. I use Seachem fertilizers: Flourish about 3 times a week, and Flourish Excel 5-6 times a week. The dosage for each fertilizer for this size tank is 1/2 cc, or 1/2 ml. The crypt also has a Flourish root tab under it. In this setup, the bettas and the plants are doing very well.

 

[TankGirl]

I would not be concerned about CO2 buildup in the air above the water level.