crushed coral w/ a plenium?

3 tangs, a dogface puffer and 2 triggers... Any 1 of those potentially overstocks a 55... You need to thin that herd before nature thins it for you. I'd start with that eel

You have those high nitrates because of the massive bioload your tank is handling... The best cure for nitrates is a 2 step process:

1.) limit the nutrients available for nitrification - ie, less fish making less poop..

2.) a natural system in place to deal with the nutrients - a DSB, macro algae (forget that with those tangs) and an efficient skimmer...

I would suggest, after you lose about 7-9 of those fish, you add a refugium to the tank and get some macro algae going in there... You can also do a DSB in the fuge which will also help to process the existing nitrate...

I hate to be a downer, cuz I know you love how all those different fish look in your tank, but to house those fish together once they reach adult size would take about a 400 gallon tank..

1 dogface puffer - 13" not suitable for a 55!
1 coral beauty - 4"
1 hippo tang - 12" not suitable for a 55!
1 yellow tang - 8"
1 yellow eye tang - 7"
1 purple pseudochromis - 3"
1 snowflake eel - 30"
1 lawnmower blenny - 4"
1 bicolor blenny - 4"
1 niger trigger - 12" not suitable for a 55!
1 huma huma trigger - 10" not suitable for a 55!
1 maroon clownfish - 6" (females only, males get 3" maybe)


That's 100+" of fish in a 55 gallon tank... I'm not a big supporter of the "xxx fish per gallon" kinda rules, but even I hafta agree yer stocking cannot survive...

Did you do any research before you went shopping?

I'm not going to slam you, plenty of others are going to chime in for that job, but you really need to do the right thing and find those fish a better home... Decide what you want to keep and act accordingly...

Plenum or not, a crushed coral bed is incapable of reducing nitrates. You need sand for that.

That aside, the answer to your problem is a bit more obvious. I agree completely with Raven's suggestions. I'm actually surprised your nitrates are that low.

And besides bioload, you have several fish that are simply not compatable. Those triggers will soon start eating some tankmates.

You may have just wanted your question answered, but you got the advice your tank needs... It may be a difficult pill to swallow, but it's easier than watching those fish turn homicidal in a few months...

Put it this way... If you had that many dogs (including pitbulls to represent the triggers and tangs, and a great dane to repesent the puffer) in the same relative space, the ASPCA would put you in jail for animal cruelty probably..

How big a tank are you building for them? Cuz it honestly will need to be freaking HUGE to house all of those properly, and I honestly doubt that mix will all survive no matter what size tank you give em... I hope your friend has a good size tank too, cuz he's gonna need it...