水草情迷

I type chinese so slow, so I use english for the rest of the post.
I am newbie in growing fishes and shrimps, and I have few question abou the filter. (First of all, I don't have much $$)

My tank is about 16"L x 12"W x 16"H ( inches ) about 50L
It is a relatively small tank, and I mainly grow shrimps ( about 10 ) in it ( later on I may add few fishes, around 3-4 )

I am not going to use any plant in it and I only use simple stones and some toys put in the tank for the habitals of the shrimps.

My question is what kind of filter I should use? people say those inside tank filter is more than enough, but I guess I may grow some fishes later in the tank, so I prefer to buy a 桶濾 filter. It has more than enough power if I want to upgrade to a bigger tank.

I want to ask which brand of 桶濾 is good, and they must be effective. Also, will the filter supply enough oxygen for the shrimps? Do I need to buy a air pump to pump the air in?

Thxfor reading.

about the $ of filter, you can see at "http://www2.aqugrass.com/phpBB2/viewtopic.php?t=1262&highlight=%B9L%C2o"
if you're not prefer use any plant in it, i think you need to buy a air pump to pump the air in.