lyndatu

Hello

I just started my first co2 injector for my plants. It's now producing bubbles, but I was wondering what would be the best way to diffuse co2 in the tank? I am currently using a basic diffusion bell, where the co2 bubbles get trapped in the bell and it "burps" when the bell is filled. But I read many comments that the diffusion bell is the worst way to go. What is the best method that I can use? I have an airstone and a powerhead. Does diffusing with an airstone or a powerhead more efficient than the diffusion bell?

Thanks in advance!

Oh, and Merry Christmas everyone!

pepetj

I'm not an expert but in my limited CO2 injection experience, dated back to August 2008, I have experimented with a few -not all- means.

If you are running pressurized CO2 -in my dreams- then an in-line reactor is what I would suggest.

If you are running DIY CO2 as I am, a tiny power-head as reactor is the way to go. As for what to attach to the open end hose, I have found that inserting a hand-fractured portion of wooden stick -those used in Chinese food- produce the tiniest bubbles of CO2. Airstones work as well as no airstone at all but the noise the bubbles produce when hitting the impeller is not welcomed by me. I have been keeping a steady -and relatively silent- CO2 injection -as measured by a DIY CO2 drop checker- this way.

Another thing: if you keep a sponge as pre-filter media in the small powerhead, make sure you rinse it weekly: a slim coat forms there that clogs easily.

Pepe
Santo Domingo

lyndatu

Thank you for the reply, pepetj!

The powerhead method sounds effective too, so it will be the one to be used by me. I attatched the co2 hose at the intake part of the powerhead with a string and the bubbles get shredded by the impellor blades and get spit out of the outake tube as a mist. There's the "sssshhh" sound that you mentioned, but since it is very efficient in diffusing co2 I can take the noise(although it is truly annoying).

I also found this nice website where they list and rate the methods of diffusing co2 in the aquarium and how they are efficient. The bell diffuser method was last on the list - with a rating of very low efficiency! But the powerhead method was second and had a medium-high efficiency rating.

http://www.aquatic-eden.com/2006/10/...-aquarium.html

But I have another question: If the objective in using a diffuser is to make the bubbles stay in the water as long as possible, should I place the powerhead near the gravel? I tried it but the gravel debris started flying around in the water. The bubbles from the powerhead disappear quickly when it hits my driftwood at the bottom of the tank. Should the powerhead be placed as low as possible? (after the gravel debris problem I placed the powerhead at the mid level of the tank, as low as possible). Sorry for all the questions!

Thanks in advance! (oh, and can you read minds? How did you know that I had a sponge as a pre-media on my filter? Hehe, I'll rinse it regularly.)

Edited to add: I almost forgot to mention this: I'm using a DIY yeast co2 injector!

pepetj

I don't read minds at all, but I use a sponge too as prefilter!

I place my tiny-powerhead reactor at 1/3 height from the substrate, some place it even higher, at 2/3. You don't need to place it at substrate level, as far as I know. Thanks for sharing that link.

I have this one for you:
http://www.aquaticplantcentral.com/f...ad.php?t=44053

What I do in my long tank (4footer, 45gal+10gal sump) is that I place it in the opposite end where the intake of the filter is at 1/3 from the substrate. I have the return (output) of the Wet/Dry filter above the CO2 reactor.

In my 29g bow (tall tank) I placed the reactor at 2/3 height from substrate so the tiny bubbles hit the Black Amazon Swords leaves, also placed at the opposite end of the HOB (which I downgraded from 350GPH to 160GPH). Works wonderfully.

Oxygen and CO2 won't compete with each other per se as dissolved gases in the water column but water agitation will lower CO2 availability while increases oxygen levels.

Since water agitation is desirable for dissolved oxygen levels and I can't have it, I use a micro-bubble wall assembly with a not-so powerful airpump (below 3psi) to complement availability of oxygen.

Keep an eye on your KH to avoid pH crashing if your water is soft/acidic.

Pepe
Santo Domingo

lyndatu

Thanks again! I'll position the powerhead in the right direction asap - the plants are getting uprooted from the current. Thanks for the link.

pepetj

What's the GPH or LPH flow in the powerhead you're using? I keep it in the low flow/cheap range (50GPH or 200LPH/under USD10.00); these units will likely suffer and get some damage due to CO2 exposure over time.

Mi Elite Mini-Filter (29g bow) is still running; a JaoLin unit stopped working in the long tank (45g) after 6 weeks or so, I replaced it with a Resun Magi-200.

Pepe
Santo Domingo