FishProfiles.com Message Forums

http://www.qsl.net/w2wdx/aquaria/diyco2.html#2

My first try at co2!!

Heres a good link i found to diy co2. Check out the diagram i like the idea of an overflow bottle(600ml) after the 2lt bottle(he calls it a gas separator). I have decided to try running the tube into my canister filter inlet to diffuse the c02 into the aquarium.

I had an idea on how to make a bubble counter at the same time so u can see when the bottle (2lt) is nearing its end and how many bubbles a sec its producing because you can't see what is coming out of the end tube into the canister inlet.

How about extending the inlet tube into the 600ml over flow bottle right to the bottom of the bottle and adding half an inch of water? that way u can see the bubbles being produced(coming from the 2lt). the outlet tube is still near the top of the bottle(600ml) so it wont allow carryover, unless the bottle fills up. the co2 dissolving into the 600ml water would still carry on into the aquarium?

what do you all think?

Interesting link. I like the diagrams. It took forever for the page to load and not all pics came through.

I'm new at co2, so I can't really comment other than to say I bought a Hagen unit (nutrafin) and tried that first. I like the bubble ladder it comes with for diffusion. But, the cannister is kind of small. I'm going to supplement it with another bottle and funnel both to the ladder.

Your idea makes perfect sense to me.

Well its up and working well, i have it diffusing into the canister filter inlet. 1/2 tsp yeast 2 cups sugar 1-2 bubbles per sec. it has lowered my ph from 7.71 to 7.05 and the co2 level is now 13ppm. Its only been a few days but some new inner shoots are green and already growing from some previously slow growing sword? type plants that have been just about dormant for 6 months

Whats the max co2 anyones got from a 2lt bottle?

i should add its a 2lt bottle going into a 30 gallon tank.
Wondering if i should buy or build a diffusor or not?

thanks...

Regarding the diffuser, what do you have now?

I believe he is running it into his canister.

This isn't the best way to inject the CO2. IME the gas tends to build at the top of the filter and then gets released into that tank in large bursts.

Since you do have a canister it would be very easy to build a defuser in the line exiting the filter before it returns to the tanks.

A simple unit made from an old (large) gravel vac filled with bioballs works very well.

Most people recommend that you do not bother with DIY CO2 for a tank larger than a 20 gallon. The general thought is that the added 2 ltr bottles needed make it too much of a hassle.

I have to disagree with this. Having more than one bottle really isn't much more work. You will need to put a valve on the line as more than 1 bottle might make too much CO2. Trust me on this. I've killed a few fish like this.

Also having more than 1 bottle and being controlled with a valve will build pressure in the system and if the system is built right the CO2 is stored and not leaked making the mix last longer. Using the overflow bottles allows not only for a place to catch spillage but also gives you more room to safely store the excess CO2.

I have 2 set ups right now. On my 40 I have 2 2 ltr bottles and on my 75 I have 3 of them. Both setups last for about a month before needing to be refilled. The 75 could go longer but I change them both out at the same day to save a little time.

Here is a pic of the one under the 75.


Shannen attached this image:

And here is the valve I use. The original idea behind this valve was to use the float gages to help me see how much CO2 is going into the tank. It turns out that they need far more current of gas to operate that the system provides so the floats are useless, but the valve still works.

You can also see how I had it going into the canister line. This is how I found out about the gas buildup in the filter. I've since changed this.

In the 40 I feed directly into a HOB filter and have not had any issues.

Shannen attached this image:

co2 , I'm now getting 16.2ppm( i have a digital ph meter at work) whoo hoo. happy with that. Yeah i got the tube going into a hole i drilled into the canister filter inlet. Im happy with the 16ppm (for now). 30 bubbles per min...no noise from the filter, fish all ok..

thanks for all the info shannen. I think i will see how the plants do with this level of co2 for now.