How Many "inches" Is A Kuhli Loach?

[nmonks]

The thing that needs clearing up for many aquarists is the belief that the air bubbles from an airstone are the source of oxygen. It would seem that you could have an electric pump circulating the water but creating now bubbles at all, and still have a good rate of oyxgen exchange because you'd be moving the low-O2 concentration water to the top, and sending the high-O2 concentration water around the rest of the tank. Conversely, a weak airstone that hardly moved any water in the tank might *seem* to be produce a lot of bubbles but would in fact not be doing very much about getting oxygen into the water at all.

Cheers,

Neale

It is the O2 concentration gradient which is the factor. O2 disolves quickly in low O2 water, slowly, eventually not at all, into O2 saturated water.

 

[Lateral Line]

Yes. A lot of canister filters, (which totally de-oxygenate the water flowing through them - bacterial action), are sold with accesories that return the water to the tank so as to maximise circulation. Spray bars angled across the surface of the tank create a rotation which draws water up the wall and across the surface for example. The air entraining nozzles have the same effect, the water is squirted down into the tank, which alone creates circulation, but the entrained air raises water in the area of the return.

Heavily planted types, (raises hand), dissolve their CO2 in the filter and use all kinds of baffles and tricks to return the now CO2 rich water to the tank without creating turbulence that will quickly knock it out again. You learn to manage your gas exchange.

 

[xoedusk]

The "inch per gallon rule" is not a stocking suggestion, it is a absolute limit. Loaches naturally live in clean, flowing, well oxygenated water, (hence the bubble fetish).

Bubble fetish. Love it.