How many fish in 20 gallon

[bostonpro]

I have a 20 gallon reef tank with a sixline wrasse and a purple firefish. A cleaner shrimp, fire shrimp, many crabs and snails. The tank seems to be doing well, nitrates never go above 10 or 15 between water changes. I just got a true perc tonight and was wondering if that is all I should get or could I maybe get another small fish? thanks

 

[bigarn]

IMO ..... No more than 3.

 

[fishcrazy2]

No more than 6 inches of fish

 

[hopkins6]

you should not get any more fish, about 6 in as what spitfire said above

 

[mrmaroon]

YIMO...you should have stayed at two. Keep an eye on the nitrates with the third fish. Most peoples tanks read 0 nitrates. Or at least they should.

 

[bostonpro]

Something I never could understand is how people's tanks read 0 nitrates. Even when I had one fish I still got about 5 or 10 nitrate reading. I thought nitrates are the end product of the biological filtration. So, if you don't have anything to remove the nitrates other than water changes, how do you people keep nitrates at 0? thanks

 

[mrmaroon]

Mine come out in my skimmer and have always tested at zero. I have add several LFS test it. A lot of people will add a refugium that will use the Nitrate/phosphate/etc.

 

[fishnerd]

A mature reef, with plenty of porous rock, good skimming, low bioload and no overfeeding will usually have a low, if not 0 nitrate level.
Bostonpro- I gotta agree with you though, I laugh when someone says "I have a 55gal with an Aquaclear 300, and 7 triggers. My levels are all at 0".
I used to manage a large LFS and used to hear that one all the time. I think its time for a lot of people with FO tanks getting 0 nitrate readings to buy new test kits, or learn to read the instructions on their existing kit.

 

[mrmaroon]

But if you are running a 55g with a 20" Euroreef skimmer, a fluideized bed filter, using a Mag 7 for high turnover, only three small fish, a lof of live rock, and water changes of 5% RO/DI per week, it certainly can be done.

 

[bostonpro]

I'm somewhat new to this hobby, so I could be wrong. But I don't think a skimmer removes nitrates. Does it?

 

[osufarker]

A skimmer won't remove nitrates, but the idea is to get the gunk out before it can break down and create nitrates.