# air-driven filters



## MyraVan (Jan 19, 2005)

I feel a bit stupid asking this... Until recenty I have only used internal power filters. Recently, with my new 58g, I have been using an external filter, so I now have some experience with those. But I don't have any experience with those most basic ones, the ones you hok up to air pumps.

I'm starting a daphnia culture, partly to feed my normal fish, partly because I'm getting some fish that only eat live & frozen food, partly because I simply like them! Reading about daphnia here
http://www.caudata.org/daphnia/
I find


> A slow aeration is needed with Daphnia as a large bubble column will strip the Daphnia out and kill them. I (and a number of others), have found that Bio-foam filters (designed for fry-tanks) are ideal for aerating Daphnia culture, and the removal of larger particles from the water is an added bonus. However care should be taken to use them at minimal air flow to avoid over-agitating the water. ... The only problem with aeration is that fine bubbles can lodge underneath the daphnia's carapace and float it to the surface and preventing it from feeding. Therefore airstones should be avoided (unless used in a bio-foam filter in which case the air bubbles combine together), or coarse airstones (or better yet, no airstones) should be used instead.


So I'm not exactly sure what they mean by a bio-foam filter. I bought one of these things at the local fish shop








and tried it out. It is NOISY! Out of the top end comes a mix of water and air: if I put it below the waterline I get the noise of air bubbles, and if I put it above the waterline I get splashing water noise.

I wonder if the following might be any better?








The blurb for this one mentions an airstone, so I wonder if this is the one the article was referring to. So what I would like to know, from people who have used this filter or something like it, how noisy is it? This is going to go in our living room (yes, my husband is actually going to let my raise daphnia in a corner of our living room!) so noise must be kept to a minimum.


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## Guest (Apr 1, 2007)

??? I'm confused??? what do you want to ask?


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## Ringo (Apr 10, 2006)

I have one similar to the 2nd one, and the only noise that is made is by that of the air pump . That and the bubbles popping at the top of my tank. Nothing to bad.


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## MyraVan (Jan 19, 2005)

Yeah, sorry I wasn't clear. The question was, would the second kind of filter be more quiet? Ringo says yes, so I'll give it a try.


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## Guest (Apr 2, 2007)

no, it was my fault. when i posted, all it said was i feel kind of stupid asking this...sorry


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## MyraVan (Jan 19, 2005)

Ah, all is clear now... I have been having trouble posting new threads recently, so I posted an incredibly short "I feel a bit stupid asking this..." to make sure it was working, and then when I found it did work, I went back and filled in the rest of the post. Sorry for the confusion!


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