Diffusing CO2

[fishb0ne]

I know this must have been discussed a million times over, forgive me. I searched the forums, also searched the net but am out of ideas.
I have a 10g planted tank with a DIY CO2 system. I use a 1 gallon jug instead of the 2l bottle. The trouble is trying to figure out a method of good CO2 diffusion.
I don't want to deal with a DIY diffuser involving a small pump and tubing, I looked into it as an option but it takes up considerable space.

I tried hooking up the line to the intake of the HOB Tetra Whisper PF10 filter, but it causes the impeller to rattle when it's sucking in bubbles.

I hooked up an airstone and placed it next to the filter intake. It still rattles when it takes in the CO2 bubbles but now most of them escape to the surface.

I played around with placing the airstone somewhere inside the filter: under the mechanical filter, close to the impeller. Same result: I see the bubbles raising up straight to the surface.

Any tips are greatly appreciated. Worse come to worse I have a Hagen Elite Mini pump with a venturi system. I tried using it but it intensifies the current in the tank even on the lowest setting AND it takes up some space.

And because I keep fiddling with this, my pH has swung over the course of 3 days from 8.3 down to 7.8, 7.6 and now back up to 8.2-ish.

Halp!

 

[An t-iasg]

I am using DIY CO2 (actually the Hagen kit, but it's still yeast and sugar) in my 5 gallon tanks. I don't use the ladder that came with the kit. I use Coralife Stubby Stone limewood airstones to diffuse the CO2 into the tank. I don't use a gas separator bottle so I do need to wipe the film off the airstone every 1-2 days. That can be a pain, but overall it diffuses CO2 into the tank quite well. I change out the airstones once a week and let the old ones dry out before I use them again. I rub them lightly with sandpaper to "renew" them also.

http://www.bigalsonline.com/BigAlsUS/ctl3684/cp18288/si1383057/cl0/coralife114stubbywoodairstone

Red Star wine yeast (I get the yeast in the blue package) produces CO2 much longer and more consistently than bread yeast.

Edit: cheaper price for the Stubby Stone (1.25" x .75") here:
http://www.aquatichouse.com/Pumps_files/airstones.asp

 

[fishb0ne]

Sweet, thanks for the info!
So you find that having the bubbles just ... bubble up from down low disperses enough CO2?

 

[evercl92]

I don't use the 'stubby' version, but I use the limewood airstones none the less. I find they give the smallest bubbles of the stones I've tried. You may find it bearable to let it flow from the limewood into your HOB.

 

[An t-iasg]

On my 5 gallon tanks, I connect the tubing from the Hagan canister right to the plastic tip on the airstone. You could connect your tubing from your gallon jug right to the airstone also and see how the bubbles flow around the tank. My CO2 bubbles literally pour out of the limewood airstone. I place the airstone very low in the tank, almost on the substrate.

On my pressurized CO2 system, I also use a limewood airstone to bring the CO2 into the tank, but I placed the airstone under a small Marineland pump to maximize the CO2 flow through ghe tank. You'll have to see how the airstone does by itself at dispersing the CO2 through the tank, or like evercl92 says, you can place the airstone where the bubbles are picked up by your filter's intake and then let the filter disperse the CO2 bubbles.

 

[Purrbox]

A 1 Gallon jug is probably going to be rather excessive on a 10 gallon. When I was still doing DIY CO2 on my 10 gallon aquarium, I only used a pair of 1 Liter bottles and got great CO2 levels. I do recommend switching to a pair of bottles so that you can rotate when you change out the mix, which will give you more consistant CO2 levels.

As far as diffusion goes, I never went the with the HOB route because of the noise and possible damage to the filter. One solution I've seen is to use a reducer to create smaller bubbles. I don't remember who suggested it or exactly what it was called unfortunately. I've used two solutions that have both worked well. I started out using a small pump to power an inline CO2 reactor. It only took up the space of the water pump and tubing. I didn't like this method as much simply because of the amount of tubing which created lots of places for gunk to build up over time. I switched to feeding the CO2 into the pump outlet and plumbing a spraybar. The affect has been very similar to the mist method and is much cleaner and easier to maintain. It doesn't take up much more space and creates better water flow.

 

[fishb0ne]

Actually although I use a 1g jug, I follow the directions for the 2l recipe, so there's plenty of room in the jug which is a good thing for any foaming that might start.

 

[Purrbox]

That's not so bad then, but I would still recommend switching to 2 bottles with a 1L mix in each. Unfortunately the variable nature of DIY CO2 tends to encourage algae like BBA. By splitting the mix in two and alternating when you change it out the mixes you reduce the highs and lows of CO2 concentration and minimize the risk of an algae outbreak.

 

[fishb0ne]

I actually have 2 jugs set-up for the CO2 system, it's just a matter of finding out the "schedule", meaning knowing when the present batch runs out.

 

[rich311k]

Do one a week. Just let them run for two weeks regardless of how it is producing. that way you don't have to worry about it.