Flowrate Of Filter In goldfish Tank, what u guys think Options

[d_golem]

After reading recent shoutbox posts, I'm starting to question my belief that a goldfish tank must have at least 10x tank volume/hour filter flowrate. A prominent member of the forum suggested only 1x flowrate and claimed only uses 2 sponge filters in his 4 ft tank.

I can see the logic in having 10x flowrate as goldfish are messy fish, but after reading some posts here and seeing that most of you guys only use air pump powered sponge filters, now I have some doubts about the 10x theory. Is that amount of flowrate really required to allow efficient filtration? Or is it only good for debris/poop control? Do simple air pump powered sponge filters provide adequate surface area for bacteria to grow to handle the amount of waste that goldfish produce?

Say u got two 200-litre tank. One is using 2 canisters with total flowrate of 2000l/h. One is using two large-sized sponge filters. Which one do you prefer?

I'm really interested in what the expert bros say.

Cheers

[gohks]

No hard and fuss rule about filtration. For me if you decide to feed alot with less frequent water change, best is to overkill on your filtration (sponge, canister, OHF, sump all serve the same purposes, and you can even have combination of all of them). You need to ensure enough areation to saturate the DO but not to create too much turbulance (trial and error you would find the way).
On the other hand, if you decide to change water very frequent and restrict your feeds, minimum filtration or even no filtration will do.