PlanetCatfish.com

hi there
have 2 small gibbies, one red spot and the other albino, and a gold nugget in a 40 gallon tank (will get a 6 foot tank when they grow). tank set up about 4 weeks with mature water/media, sand, rocks and driftwood. lots of water movement with fluval 204 agitating water surface. all nitrates/ammonia/nitrites good. notice that at times my red spot gibby will display stress colouration - paler in areas, symmetrical - and i think it coincides with noisy footsteps (wooden floors) and settles when vibrations disappear. is this normal? obviously can't see any stress colouration on pale gibby. gold nugget doesn't do this. all food being eaten, seem happy enough. a while back seemed to be going to surface for gulps of air, so changed the level of the filter output to above water surface, now not doing this so much. (no airstone).

Also do you think my fluval 204 is enough fo filtration? should i also get sponge filter?

Yes, these fish will have a stress colouration which is lighter/darker "blotches", almost like stripes or lines across the back.

If you feel that you need more filtration, I'd recommend getting either another internal filter, or even better, an external canister filter. They are more efficient than a sponge filter. Sponge filters are good for some things, but if you have a couple of poo-machines like the Gibby's in there, you're probably better of with a power-filter of one kind or another.

That will also help circulate more water, which will help getting oxygen to the fish.

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Mats

i think my fluval 204 is an external canister filter. am not sure as to the exact term, but it is an external unit filled with sponge and ceramic hoops and has a high flow rate. all nitrates etc are ok. i was asking about the sponge filter because i read on this website that they are a good biological filter, and they are cheap, and I finally found one in the shop here. I guess the stress colouration is prob quite common - notice my bristlenoses sometimes do it in my other tank - female more than male.

so does it sound like i already have an external canister filter?
if so, it is probably overkill to add a sponge filter.

Yes, it does sound like you have an external canister filter already. They are pretty good for biological filtering, whilst a sponge-filter will probably give you a bit more bio-filter, I don't think you need it unless your nitrate is going up.

The measure of whether your filter is sufficient or not is really how high your nitrate goes. If it doesn't go too high, then you don't need more filtration. [Obviously, if you have "dirt floating around", you may consider that as a filter purchasing criteria too].

In your case, I'd probably go for a cheapo power-head to get more water movement, and perhaps an air-stone too. I like the look of those long air-stones, but that's a personal opinion thing. Air stones don't add much oxygene in the process of bubbling, but they make water from the bottom rise to the top and circulate a lot better than the same water without an air-stone, and that helps keeping the water well oxygenated.

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Mats