Powered co2 reactor question (sort of long)

[Greg J]

I’ve built myself a powered co2 reactor like the one in this article:
http://www.qsl.net/w2wdx/aquaria/diyco2.html

But I’ve made a few modifications. Instead of a sponge for the inlet filter, I’m using my under-gravel filter as a pre-filter. The problem with that was I was drawing water from the bottom of the tank, and then it was exiting from the modified gravel tube near the bottom of the tank – basically I had very poor circulation. So I rotated the power head 90 degrees, so the modified gravel tube was horizontal near the top of the tank. The circulation was much better. But it looked terrible (actually I wasn’t crazy about how it looked in either orientation, but the second was worse).

So I put a longer piece of tubing on the outlet of the power head. Ran it up into the hood. Put the modified gravel tube up there. Attached the cap off another gravel tube to the outlet of the modified gravel tube, and another piece of tubing to that. And ran that piece of tugging over to the top front of the tank. The tank looks much cleaner and so far no problems.

I also filled the unused portion of the modified gravel tube with ceramic bio-media. I figured I’m pumping water through it, I might as well get some filtration out of it too, along with the co2 diffusion.

My question: Would there be any reason not to add a second air-stone to the modified gravel tube, and run an air pump to that to help oxygenate the water for the fish, since the air stones have been removed from the under gravel filter and are no longer oxygenating the water?

Thanks

 

[Ajordan]

Interesting question. From what I understand you are asking if you could turn your CO2 reactor into an "air" reactor as well. In short, I don't see why it wouldn't work but I don't think you would be doing your plants any favors. There wouldn't be much point in running CO2 while running an airstone.

If you wanted to run the airstone at night and the CO2 during the day (as some people do) then having the air bubbles go through a reactor would likely make the injection more efficient.

I don't know if that answers your question... I have never heard of people using a reactor for an air pump. I don't see any reason why it wouldn't work. To me the bigger question is why?

 

[Greg J]

To me the bigger question is why?

I'm just concerned there might not be enough air (specifically o2), getting into the water for the fish now, after the changes I’ve made.

 

[Notophthalmus]

The airstones don't put much O2 directly in the water, it's the surface agitation they cause that does the trick. If your CO2 bubbling is causing as much surface agitation, then it's doing the same amount of work.

Besides, the CO2 should be increasing photosynthetic rate, and therefore O2 production, of your plants.

 

[StereoKills]

^ Exactly. There's really no point in running an airstone while adding co2 (unless the lights are off). It defeats the purpose of injecting co2.

 

[Greg J]

The airstones don't put much O2 directly in the water, it's the surface agitation they cause that does the trick.

I understand that. It’s just now there is a LOT less surface agitation compared to when I was running the air-stone powered under gravel filter.

Besides, the CO2 should be increasing photosynthetic rate, and therefore O2 production, of your plants.

True, but is that going to be enough for the fish? (not arguing, just asking)

 

[Notophthalmus]

So many variables there- surface area/ volume ratio of your tank, bioload, plant mass, temperature, lighting; it's a hard question to answer. My guess is that if your tank is fairly lightly stocked, the fish will have plenty of O2. If it's very heavily stocked, you may have trouble. Just give it some time and observe your fish; if you don't see a decrease in activity, an increase in gulping, or other warning signs, then you're fine.

 

[Greg J]

Cool, thanks.

 

[Greg J]

Oh Yea

Here's a pic:

 

[Ajordan]

looks like a pretty sweet device.