CO2 into intake of HOB filter. Does anyone do this?

Jeanine

Junior Poster
May 7, 2009
3
0
1
Terrace, BC, Canada
I have a 55 gallon tank that has 110 watts of light over it. I'm on a budget, so am doing DIY CO2 using 2 2 liter bottles with the hagen diffuser ladder. The problem is, I see the bubbles are still quite big and fly to the top at the end of the ladder. I would like to find a better method of diffusion, but I am on a budget. I have a HOB filter and was thinking maybe I could run the hose into the intake. Will this work?
Has anyone else tried it?
 

shoggoth43

Lifetime Charter Member
Lifetime Member
Jan 15, 2009
1,092
11
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This should work fine for what you have in mind. Depending on what you have for a HOB, you may get the odd "burp" of CO2 out of it periodically as the gab bubbles combine and build up. The more common "spill back in over the top" designs probably won't have that issue.

-
S
 

Henry Hatch

Guru Class Expert
Aug 31, 2006
179
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16
Jeanine;36609 said:
I have a 55 gallon tank that has 110 watts of light over it. I'm on a budget, so am doing DIY CO2 using 2 2 liter bottles with the hagen diffuser ladder. The problem is, I see the bubbles are still quite big and fly to the top at the end of the ladder. I would like to find a better method of diffusion, but I am on a budget. I have a HOB filter and was thinking maybe I could run the hose into the intake. Will this work?
Has anyone else tried it?

Running a 55 gallon on diy co2 is going to be a challenge. I would probably use 6 or 8 liters of co2 mixture. I would suggest that a one gallon bottle of diy mix would do better than 2 2liter bottles. The additional size will support a larger population of yeast cells. Running the co2 line into your HOB filter will help. You might also try using a power head mounted on a piece of 1" uplift tube. Attach a small piece of rigid airline tubing to the co2 line. Insert a small piece of dense foam into the bottom of the of the uplift tube and insert the co2 line into the foam. This will create smaller bubbles going into the power head so that the bubbles will be chopped up into a mist.

Aim the output of the power head in the direction of the output of the HOB.

Henry
 

RlxdN10sity

Prolific Poster
Jan 28, 2007
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6
I did this once with an Aquaclear HOB. I drilled a hole in the bottom of the main reservoir under the sponge filter and put an 1/8" NPT brass nipple x 1/8" barb into it and connected my CO2 line to it. Sponge caught the bubbles and the water passed across the sponge on the way back to the tank. It worked pretty well, I do not remember having any particular problems. I've since gone to canister filters and DIY reactors. If I were to do this again I would probably try to force the gas through some kind of diffuser like a wood block or something to get smaller bubbles inside the reservoir.
 

MrFishy

Junior Poster
Mar 24, 2009
3
0
1
Petaluma, CA
I agree with Henry here- running such a large tank on such little co2. Luckily you have a reasonable amount of light. I might also recommend a couple more yeast reactors to provide more co2, but more importantly I'd recommend a better method of co2 diffusion-
DIY internal Reactor, great for Yeast CO2 users!

It's cheap and very effective. Better to use the little co2 you have very efficiently. I will say it'll probably take a little more like 30 minutes and depending on the price of a powerhead in your area it might cost a little more than $11.

I did try running my CO2 into my HOB inlet and it got air-locked. Tried this with two filters actually, didn't work either, same problem. Maybe you'd have better luck drilling the bottom. Either way I never really liked the idea because I figure a lot of the gas would escape from the actual filter (what with all the surface swirling around) and from the waterfall.
 

Jeanine

Junior Poster
May 7, 2009
3
0
1
Terrace, BC, Canada
Well, I used a 4 lt bottle for my new batch of DIY CO2 and ran it into the HOB filter intake. I don't have a bubble counter, but I am getting a good group of bubbles every second (they go up the intake tube to fast to count). I see lots of really tiny bubbles in the water column coming out of the filter, so I'm assuming that these are little bubbles of CO2. I did a PH test and my PH went from 7.6 to 7 since last night (I just hooked it up yesterday), and this evening the plants have lots of bubbles on the leaves and rising to the surface. No air locks as of yet.
Now what I'm wondering is, when it's time to change my other 2 lt bottle, should I switch it to a 4 lt. ? I'm worried about killing my fish. Right now they seem to be doing fine.
I've attached a picture of jungle of a tank.:)

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