co2 question

FilteredFun

... conventional wisdom says its the surface agitation caused by the bubbles that causes the majority of the gaseous exchange and not the bubbles rising through the liquid.....

That was my thought and the reason I tossed out the idea of using a HOB filter to generate a lot of surface agitation.

you will have to deal with the increased noise.

Agreed. That is something that I would need hear in person to determine if the noise was pleasing [much like a fountain] or distracting. If it was pleasing, it could achieve a dual benefit. I want to have a canister filter [Ehaim or Fluval] and a HOB Bio-Wheel running simulataneously. My reason is to have a back-up should one system fail.

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I am also intrigued by the simple design of a Bubble Disk powered by a Rena airpump. This simple tandem would certainly achieve the needed gas exchange at the tank surface.

http://www.drsfostersmith.com/produc...9&pcatid=10669

and

http://www.drsfostersmith.com/produc...fm?pcatid=3724

However, I had read that aeration should only be done when the lights are turned off in a planted tank.

Do all of you agree from your experience(s)?

Thanks,
Matt

Jay

Yes but why???? <-rhetorical question I'm going to tell you.

You only need to inject CO2 during lights on when plants are using it.

To be effective the CO2 gas must reach a dissolved level of 20+ ppm.

Heavy surface agitation tends to "gas off the injected CO2" therefore it is counterproductive.

No Rocket Science here


I know I will get cards and letters on this but...IMO the bio wheel is the best, most clever, and effective marketing device to sell filters and unnecceary supplies that I have ever seen.

Jay

FilteredFun

...IMO the bio wheel is the best, most clever, and effective marketing device to sell filters and unnecceary supplies that I have ever seen.

I actually appreciate an honest opinion. That's what makes these forums so fantastic. The immediacy of assistance and honest opinions based on both observations and first hand experiences are extremely helpful.

I would certainly enjoy reading your reasons behind this assertion. I was all but convinced that a Bio-Wheel would be the perfect back-up to a canister filtration system. Part of my thinking is based on the simple addage that more is better. Other reasons that I previously stated were surface agitation [keeping in mind that I have ruled out CO2 injection] and acting as a fully functional back-up in case of canister failure.

: FilteredFun

Jay

IME canister failure is rare, does happen, but rare. I would think the worry issue would be circulation and surface agitation to maintain O2 levels in the tank if you think you would be down more than a day or two.

I run canisters on my show tank Rena 3 and Rena 2 plus a Rena Smart filter with an Eheim Surface Skimmer. They are very reliable filters. Most of us who have been in the hobby for a while always have an old HOB in a closet somewhere that could be used in an emergency.

My thoughts on the Bio Wheel: If you really understand the nitrogen cycle, and the roll of both Heterotrophic, and Nitrifying Bacteria Colonies, how they form and what they do then some issues become clear. The whole claim to fame is that the Wheel gizmo facilitates bacterial colonization to deal with ammonia and nitrites. Given that from primordial times these bacteria can, will, do exist and will establish colonies everywhere in the aquarium. Why would you want to encourage them to be in one area only, which if you think about it is extremely vulnerable.

The nitrifying bacteria colonies will grow or shrink in direct proportion to the amount of ammonia/nitrites available from the fish, heterotrophic bacteria activity, food etc. The bio wheel really has nothing to do with that.

Now thats for a non planted aquarium. In a well planted tank the plants are going to uptake ammonia, nitrites, and nitrates plus phosphate iron etc. etc. Leaving the bio wheel as superfluous.

IMO the bio wheel is an unnecessary expense and a very marketable gadget.


Jay

wl_keller

I always just assumed the Bio Wheel was on a HOB filter so that whenever you replaced the disposable filter media, the bacteria colony didn't have to start all over again. I rarely ever used it and it never seemed to make a difference. About all it ever seemed to do was make a splashing noise when the water level got a little low.

Another filter that I had used a sponge in front of the filter media to do the same thing, although probably more effectively.