Quote Originally Posted by wilomn View Post
You can keep anysize saltwater that you can fresh. The problem is that salt water fish tend to be more delicate and you have to aritficially maintain water conditions. The smaller the volume of water the quicker the changes, both for good and ill.

A 20L is doable, just get good equipment and go to a real fish store, not a petco, to get some advice from people who actually keep saltwater fish.
Wes nailed it. Larger systems are much easier to maintain, water parameters tend to change much more rapid in a smaller tank. You can set up a "low maintenance" nano tank for a single clownfish.

Here is a 12g Nano Reef that I had setup for a single (Amphiprion percula) Percula Clownfish aka "Nemo's close cousin"



The maintenance of this tank consisted of a 2 gallon waterchange with freshly made saltwater every 5 days, and I replaced the evaporation with RODI water on a 2-3 day basis. Feed minimally, and I simply dosed calcium and other trace elements to my desirable level, although water changes helped with much of that.

I kept the tank mainly for corals, so I kept the specific gravity a bit higher than I would for a fish only tank.

If you're interested in smaller setups check out:

www.nano-reef.com or
www.reefcentral.com under the Nano Tank Section of the "Special Interest Forum"

If you have any other specific questions feel free to PM me.

Jason