Rank these DIY style CO2 reactors

[morleyz]

If you were using DIY CO2 but wanted to have the most effective diffusion on a budget, what is the order of preference you would use for the following reactor types.

1. Bell Type
2. CO2 into HOB filter
3. CO2 into Canister filter
4. Airstone
5. Other (please specify)

Thanks!!

[GulfCstAquarian]

Out of the four you specify, I'd rank them: 3, 2, 1, 4
Canisters are expensive, though and a HOB filter will do just as well, although you'll lose some CO2 through surface exchange at the "waterfall". For a budget, I just stick with the HOB.

But my favorite "other" is simply to buy a small powerhead like a Rio 600 or Aquaclear 201 ($12 at bigalsonline.com) and let the powerhead break up the bubbles and disperse them among the water. Couple it with a gravel tube to capture those tiny bubbles and you've got one heck of a reactor for a couple bucks. Most planted tanks could use the extra water movement as well. Not vigorous, and definitely not aimed at the surface, but enough to carry those much-needed nutrients to all the leaves in the tank.

[djlen]

I agree with Gulf, except for a larger tank I use the AC 402 power head which does an excellent job for me.
Len

[Richer]

In order of preference.. (highest to lowest)

1.) Other (read below for more info)
2.) CO2 into canister filter
3.) CO2 into HOB filter
4.) Other (read below again)
5.) Airstone
6.) Bell

1.) I essentially do what Gulf described. I use an Aquaclear 802 powerhead (its what I had laying around) with a gravel tube attached to it at a 90 degree angel with a sponge stuffed in it. Works great, and it was cheap. Its good for larger tanks.
2.) This method isn't too bad neither, it minimizes CO2 loss since a canister filter is sealed (or it should be), the impellar within the filter chops up the bubbles nicely, and the filter media provides good spots for resistances.. increasing the amount of time of contact time the CO2 bubbles have with water. Which essentially gives you nearly 100% diffusion. Ranked #2 since some people don't have canister filters, it can be somewhat noisey (with the impellar making noises from the bubbles), and some filters might experience air locking. Works for larger tanks.
3.) Works ok. From what I hear and read, aquaclear filters are best used for this method. Essentiall the same as a canister, except the system is not sealed, so there will be CO2 loss during the diffusion process. Not only that, but the filter might cause some excess surface aggitation, leading to more CO2 loss. Attach a sponge to the outlet of the filter to reduce surface aggitation... I do that on the AC mini I have on a tank in my room... there's almost no surface aggitation from that filter right now. I would suggest using this method for smaller to medium sized tanks. It can be somewhat noisey, since the impellar is chopping up the CO2 bubbles.
4.) Powerhead diffusion. Works pretty good also... the impellar of the powerhead chops up the bubbles nicely, and shoots them out as a mist... you can also attach the CO2 line to the arriator of the powerhead. Works fine for smaller to medium sized tanks, it can be somewhat noisey with you feed the CO2 via the intake of the powerhead.
5.) Airstones work ok... you need to find airstones that will give you the smallest sized bubbles possible... wooden airstones should do the job. It also helps if you can direct some water flow over the path of the ascending bubbles, to increase the amount of time the bubbles are in contact with the water. I'd suggest this method only for small tanks.
6.) I tried the bell method once, and I'll never try it again. The bell takes up far too much room, and in my experience very inefficient (much more than the airstone). CO2 would collect under the bell.... and continue to collect, until a large amount of collected CO2 escapes from the side in the form of one large bubble. Even with waterflow underneath the bell, I got little diffusion (compared to even an airstone). It might work for you, but I wouldn't suggest it.

HTH
-Richer

[merlin4260]

Nobody had posted here in a bit, but I thought I would spread this web page a bit more. DIY CO2 Reactor (http://www.csd.net/~cgadd/aqua/diy_reactor.htm) That links directly to the reactor how to, but the rest of the site is really good too.

[doxponygirl]

I am usins the DIY co2 with an airstone attached. It is putting out between 20-40 tiny bubbles a second. I saw you talking about using the power heads. I have whisper 970 in my tank with the little air hose that sticks above the water line to control how much air I want in the tank. Is this the same place on the power head that the co2 DIY should be hooked up to?

[Skittyfish]

This is what I use
http://community.webshots.com/sym/image4/0/10/35/70001035ljPzcx_ph.jpg

If the picture doesn't show, click on pictures in sig line and go to the odd and ends album.