CO2 vs Oxygen - the battle!

[nerbaneth]

Hi,

This is my first post here (or in any fish forum.. this one seems nice)

(1) I have heard(read) when you add CO2, you do not want surface agitation or air bubbles because you will loose all(or most) of the CO2 to the air.

My problem is that after a few days of CO2 injection all my fish are breathing really REALLY hard. So at this point I turn off my CO2 and point my power-head at the surface, and my fish are fine within a few hours - 100% better after a day or so.
Currently I am doing this routine every couple days which I am sure is horrible for my fish.

Is that rumor(1) true ? How do I keep my fish and plants happy at the same time without putting my fishies in harms way?

My setup:

90 gal tank
ehiem canister
5gal igloo cooler DIY CO2 (I was sick of using four '2 litres' hooked up together)
fish - blue rams, pleco, pictus cats, bala sharks, and a little yellow dwarf cichlid (I can't recall it's name right now)

I've had this tank setup for a year or so, but I finally decided to take out my MASSIVE hornwort (bush, plant, TREE?!) and (about a week ago?) bought 10 different types of plants online (approx. 100-150 individual stem plants plus glosso and four leaf clover) So in a 90 gal it is not heavily but not lightly planted.

 

[VaughnH]

It would help you a lot to get a drop checker (http://www.barrreport.com/articles/2661-drop-checkers-co2-indicators-why-how.html) and use it to get an idea about how much CO2 you have in your water. Then you can make a better judgment about what to do next. It isn't true that you should try for no surface disturbance when using CO2. It is much better to disturb the surface enough to get some rippling of the surface, in order to get more oxygen absorbed into the water. When you use DIY CO2 for a 90 gallon tank it isn't likely that you will ever have too much CO2 in the water, but it is still possible.

 

[nerbaneth]

I will defiantly look into a drop checker.

my 5 gallon yeast reactor is the equivalent of 9.5 of the standard 2 liter bottles people use for (up to?) 20 gallons as I have read. so I should have enough CO2 for almost 200 gallons? I am sure that is an overestimate but either way my fish suffocate when I have it on. I will try cutting the amount of CO2 I let through the needle valve to half and see how it works - along with a possible drop checker.

Thanks!

 

[Mooner]

The other issue is circulation/flow. Inadequate amounts of these can cause your problem. Try an extra power head at the back and high in the tank pointing down diagonally to the front. Better circulation will also help stop reactors from air locking.

 

[VaughnH]

How are you using a needle valve on a DIY CO2 system? That can be hazardous, since it causes a build up of pressure in the container of yeast/sugar water. It is hard to regulate the flow of CO2 with a DIY setup.

 

[nerbaneth]

I made a needle valve out of brass parts (I work at ace hardware)
and then I siliconed and screwed it in. Then I poked tiny holes with the smallest syringe needles you can buy (ace again) in the silicone and put a small dab of hot glue on top of that. when it gains up too much pressure the hot glue either flys off or just breaks and lets air through.

 

[VaughnH]

Very interesting! I assume you have used a soap bubble solution to check the whole thing for leaks? Working at an ACE hardware store certainly does have advantages. Now, you just need a drop checker, and working there you should have lots of materials to work with for a DIY version.