QUOTE(goldfries @ Jan 18 2007, 09:41 AM)
just sponge and other filter media inside. connect the air-pump to it.
HOB is nice on those small tanks, BUT please be careful to choose appropriate flowrate.
HOB will have water coming down like waterfall, so in a small tank sometimes it's like a whirlpool.

ooo tak perasan plak these types of filters
QUOTE(geediver @ Jan 18 2007, 11:53 PM)
IMHO, common goldfish will outgrow your cute tank. Your particular type that you have right now, will however decimate most types of plant (a little nibble here and there, lo behold no more plants). I asked that very same question back when I started, most often than not, everyone says that a 'naked'/empty tank is the best for goldfish. I've since gone for the naked look, too.
HOB varies in costs and sizes. Hunt around the various LFS in town, but please ask the people there what fits your tank size (they should stock similar tank sizes there), just try the ones they recommend against their stock tanks for size. Otherwise, you might be in for a shock when you get home.
There's a list of fish shops on 1 of the threads.
Btw,

hand itchy again, went and got myself a 1' tank. I should stop going to LFS altogether from now on. Keep trying to improve myself.
fortunately i live far from those big/fancy/better LFS. else will end up go there and shop everyday hehe
QUOTE(SweetPuff @ Jan 19 2007, 10:25 AM)
How can we tell female fishes from male? Like for neon tetras, guppies and goldfishes?
i only know how to differentiate guppies. goldfish and tetra dunno