View Full Version : is my tank overstocked?

01/12/2007, 12:20 AM
I set up a 75 gallon reef tank about 3 months ago. I have roughly 100LB of live rock and a 14 gal sump. Coralife super skimmer 125. Mag 12 pump for main filtration and 3 100gph powerheads. I made the tank and sump myself out of acrilick. I'll add pictures soon. It is a corner tank and the sump is L shaped. The tank is 30 inches tall and the live rock is about 5 inches away from the water line. I have some coral: 3 leathers, 1 abae anemone, torch coral, muchroms, open neon brain, sun coral, Orange plating montipora and a couple more odd balls... The sump is loaded with spaghety algae. ...

I think I got everything. Now to the problem. I think my tank may be overstocked. I have the following fish in the tank.

2 chromis
1 blue demsel
1 3 stripe demsel
1 foxface Lo
1 Yelow Tang
1 fire fish
1 watchman goby
1 maroon clown
snails and crabs all over.

I have almost no hair algae since the yelow tang and the foxface are eating nothing but that. However I do have cyanobacteria all over the sand bed. I have been fighting it for the past week but I can't seem to win the fight. I feed the coral about once per week and the fish get some of that food also. I stopped feeding flake roughly one month ago.

All my levels seem fine except for nitrates seem to never fall below 20 ppm. As soon as they hit 30 ppm i do a water change and they go down a bit...

What do you guys think? How do I kill the cyano? What do I do about the Nitrates?

Thank you for all your help,


01/12/2007, 12:31 AM

That's on the heavy side for stocking, I think, since the tank has a refugium. If most of the fish are small, the tank should be fine for a while.

I would target around 750 gph total flow through the tank as a minimum. Are the powerheads 100gph or 1000 gph?

How much and what is being fed? Just the coral food?

Growing and harvesting a macroalga might help a lot.

01/12/2007, 12:55 AM
i only got 4 in my tank and i think thats about max for my 75

01/12/2007, 10:38 AM
I would say that you are nearthe upper limit of stocking. Your nitrates suggest this if you aren't overfeeding as the tank can't keep up as well with the waste. I would drop the 2 damsels first just b/c they aren't my favorite fish and can become nippy

01/12/2007, 11:13 AM
Cyano break out at 3 months is a very common occurance. In my case it just went away on it's own. Clean it out when you can, but don't panic over it and start putting a bunch of chemicals in your tank. Give it a few more months before considering it a "problem".

I'd never have put that many fish in a three month old tank... but that's just me. My tank is 7 months old and I'm thinking about adding a second fish. I've had 5 total at one time... one jumped, two died of ich/stress and one was healthy, but just vanished one day. I'm down to just the butterfly, but he's doing really well.

01/12/2007, 01:32 PM
Hello Schplitter,

in my opinion it is quite overstocked, particularly as it is only a couple of months old. Also remember that the yellow tang and the foxface get quite big and in a short time. In my opinion you tank is too small for either of these fish.