what's a good filter for a 20gal long spawn tank?

[HatsuneMiku]

^_^ just as the title asks

i know everyone says a sponge filter ... but most of the sponge filters that are available here don't look very appealing

thanks in advance for any advice and any suggestions would be greatly appreciated !!

[Sakura8]

I'm using a Marina Slim S20 filter on my 20gL. The outflow isn't too turbulent and the intake tube has a sponge prefilter on it so that would help prevent any fry from getting sucked up. Plus, the intake can be dropped lower into the water so it would work if there wasn't much water in the tank. Although, the outflow would then become far more turbulent as it has to cascade down further.

Sadly, unattractive as they are, a sponge filter probably is the best bet for that big of a tank. AngelsPlus has some custom ones that fit nicely into a corner and if you get the 40ppi, you don't have to worry about any fry getting sucked into the filter.

Sponge Filters for aquariums

Another option is using a gang valve and hooking an airpump up to several smaller box filters like these:

Lees Large Triple Flow Filter

Using two or three of the large size should provide enough filtration for a full spawn tank.

[HatsuneMiku]

ooo thank you very much for the links and your suggestions!!

those sponge filters from your link are actually a lot better then the one's i've seen sold around here .. and i didn't mean to make it sound like appealing for the looks of the tank .. i meant for functionality .. the one's so far that i've seen sold around here are hugely clunky and porus looking that i would be worried a fry could get stuck in there .. and i'd really like to be able to like cut a piece off .. and put it in my already cycled tank .. so bacteria can grow on it .. then be able to fit it back into the spawn tank .. or should i just put the whole sponge into my cycled tank? and then re-attach it when i put my pair in? will the bacteria die without the air bubbles on while they are spawning and doing their thing?

another of my worries is the initial low water level (about 3-4 inches) .. and how that is going to change as the fry grow and as i fill the tank .. would i need to set up another filter after?

[Sakura8]

Hatsune, I agree. I've seen a lot of sponge filters that don't seem very effective at filtering because they're so porous. The filters from AngelsPlus can also come pre-seeded with bacteria, although the problem with that is if there's any bad bacteria or parasites in their cycling tanks. You're safer and better off cycling in your own tank. If it fits, I would just put the whole sponge in the cycled tank, cycle it, and then put it in your spawn tank. Perhaps buy two filters, one to keep in there for the actual spawning and one to keep in there for the fry. I think, and I'm not 100% sure, but I think OFL said that as long as you have some living organism in the tank, the bacteria will survive without the airbubbles. I'm sure someone who knows more in that regard can come along and clarify though.

I think once you get the spawn tank filled up more than halfway, I would set up a second filter in the opposite corner. But for me, I think one filter should be fine.

[Tisia]

I think generally people wait till after the fry are free swimming to put in a filter. I waited until the tank was filled and depended on the live plants and the added water to keep the water quality good in the meantime. I'm at about 3 weeks now with probably around a hundred fry, so it seems to have worked for me, lol

[dramaqueen]

You don't want your filter to be too strong so the fry won't be sucked in.