The Best for DIY CO2 Diffusion?

[jbarr]

So I have DIY CO2. The bubble goes into a bubble ladder (Hagen I think?) and then after the ladder the bubbles are caught in an upside-down film canister. Are there any ill-effects to that? Or is it basically worthless?

I was wondering if I would be better off sticking the tube into my HOB intake. What do I do with the water level if I do this? Does it matter?

Finally, I have a powerhead that I have yet to set-up on any of my tanks. I heard it's good for chopping up CO2 bubbles, but I'm afraid the flow will be too strong.

The tank is a 20 long.


What is the best method of diffusion?
TIA

 

[Doog]

If you have a powerhead, id say go ahead and do the inline reactor.

 

[Purrbox]

In general powered diffusion is going to be more efficient than passive diffusion like the bubble ladder and film canister. To improve your diffusion you'll want to switch to powered diffusion. This can be as simple as feeding the CO2 directly into your filter and allowing the impeller to chop it up. You could build an inline reactor powered by a water pump as Doog suggested, or you could use the mist method. All of these methods work well and can be very effective when combined with DIY CO2, it's just a matter of picking the one that works best for you.

Plumbing the CO2 directly into the Filter - This is probably the least expensive and easiest solution. It can make the filter noisy and will cause some of the parts to need replacing sooner. It works better with some filter models than others. It can cause airlock in some filters.

Inline Reactor - Just requires a bit of PVC building and is very inexpensive. Gets great results and keeps most of the CO2 equipment out of the tank.

Mist Method - Nearly as inexpensive and easy as the Filter method. Best results as far as diffusing CO2. Will have lots of tiny bubbles floating around the tank which some people find aesthetically unpleasing. Some feel it works too well on their tank, resulting in excessive dosing and trimming.

For all methods of diffusion you want the water level to be high enough that the filter isn't causing a lot of splashing. Otherwise it will gas off a larger portion of the CO2 you are working so hard to inject. If you can keep it so that it's causing a nice ripple but no more this is best as you will still get good gas exchange but not so much that you're loosing lots of CO2.

 

[Angry the Clown]

You mention that you have a HOB filter. That may be cause for low CO2 levels due to the surface disruption of the water returning to the tank. If that is the case, than using the powerhead to venturi the CO2 into the water column may be your best bet. Is your powerhead output adjustable? If so, just turn it down some, and point it somewhere where the flow will not disrupt things.

 

[jbarr]

Could someone enlighten me as to the Mist Method?

Also:

HOB vs. Powerhead (I would remove the HOB, very small bioload in this tank)

 

[Jman17H]

The mist method is very simple:

Use a limewood airstone (I use coralife) and place it below your powerhead so that the powerhead sucks up all the bubbles and spit them out all over the tank.

I also have now created a sort of bell on my powerhead intake so that almost every bubble goes into the powerhead. I used a small touperware container and made a larfe hole to place it on the intake, a hole for the airstone to attach inside and a few small holes in the top so the powerhead is never sucking airpockets.

I would not get rid of your HOB! A powerhead is not a filter and while you do not need a lot of filtration in a planted tank, I doubt you would want none. just keep your water level at the outtake level of your HOB so it is not splashing.

 

[Purrbox]

Actually it's quite possible to run a lightly stocked tank without a filter. The nitrifying bacteria will still live in the other surfaces of your tank (glass, gravel, plants, etc). You just need to use something like a powerhead to provide the water circulation instead of the filter. I have four tanks, none of which currently have a filter, and the plants, fish, and shrimp are all thriving.

 

[jbarr]

That's what I'm saying I guess, is that the filter isn't THAT necessary w/ a good amount of plants, small bio-load and some source of circulation.

What would be better, diffusion through HOB or Powerhead?

 

[zenkatydid]

i would think that a ph is going to be better, as it puts the co2 into the water without having to splash over the waterfall and potentially offgas.