Things to be careful while using Co2

[pillairp]

Hi,

I have a planted tank and which is running for last 5 month, now i am planning to install CO2 system to the tank. Just need your help in making sure that i dont do any mistake or anything which can harm the fish or the setup of the tank.

mine is a 4 ft long 55g tank with varities of tetras. Currently ordered for 2 kg CO2 bottle and 3 in 1 - Diffuser+bubble counter+ safey lock.


Regards,

Rajesh

[KingFisher]

You may need to run an airstone at night to drive off the ecsess co2 from the water. Watch for your fish to be gasping at the surface in the morning, then you will know.

[pillairp]

as of not i am planning to keep it off during the night. will that be ok?

[KingFisher]

This can happen even when you keep it off at night. The plants actually stop using co2 at night and use up some of the o2 in the water. Levels can drop significantly without enough surface agitation.

[funkman262]

You should also purchase a glass drop checker which will allow you to estimate the co2 concentration. The way it works is when the liquid is blue, the co2 concentration is low, green is in the appropriate range, and yellow means too much co2. I use diy co2 in my 90g planted tank and my drop checker is typically on the border of green and yellow. Although I don't run any type of airstone to agitate the surface to blow off excess co2, I've never had a problem with my fish gasping at the surface at lights on. However, that doesn't mean you won't have that problem so be sure to take KF's advice and check the fish at lights on (when the co2 should be at its peak).

[dozerd8]

Where can you buy a glass drop checker.

[funkman262]

I got mine cheap on ebay. Unless you have the equipment to make a 4dKh solution, make dure you buy one that comes with it. Also, if you don't have a liquid pH test kit, make sure it come with the blue drops.

[rich311k]

Go very slowly, watch your fish for any reactions. Mostly gasping and sitting at the top. A drop checker is a almost a must. When you start and when you make any changes be around so you can observe the effect of the change of CO2 levels on your fish.

[BrandonBCA]

For the 4dkH solution you don't need anything more than a 1/8 teaspoon, 2 liters of distilled water, baking soda and something to measure mLs(a syringe, small measuring cup, or something similar)

4dkH=71ppm CO3
1/8tsp baking soda=.6grams
for 1dkH solution=30 mg baking soda so 600/30=20dkH solution if 1/8 teaspoon is added to 1liter
20dkH=214mgCO3/l or .214mg/mL so it will take ~330 mL for 71mg CO3 from this solution

Basically, the steps are dissolve 1/8 level teaspoon baking soda in 1 liter of distilled or RO water, then take 330mL of that solution and add distilled water to a volume of 1 liter. Add the solution to the drop checker, add pH indicator(bromothymol blue based like the basic API pH test).

Really though, a 4 dkH solution isn't necessary, any known kH solution that is only buffered by carbonate will work with the kH/CO2 chart. 4 dkH just gives a nice transition from blue(less than 25ppmCO2), green(25-35ppmCO2) and yellow(more than 35ppmCO2).

If you use a drop checker, don't put it right next to your diffuser, since that will be the most CO2 rich area and won't give you a good idea how the rest of the tank looks CO2 wise. Also, aim for a stable CO2 level rather than a specific number. It shouldn't be a problem to get 30ppm in a 55g but a stable CO2 at 20ppm will give you better results than bounding back and forth if you can't.