Just lost all our fish!

[unshaven]

Recently in our 20 gallon reef tank we noticed that our clownfish were making strange with one another.  They were occasionally rubbing up against rocks and the filter.  There were no white spots or slime I could see, so we did a little water change just for safety sake. 

We also recently had a red algae problem and successfully treated the tank for it and put in some phosphate remover in our filter.  When we tested the water there was less than 0.25 phosphate, ph 7.9, Nitrates at 2, ammonia was very low, temperature at 78 degrees and salinity at 1.025.

Everything seemed fine.  we did some cleaning in the tank and shut it down for the night.

Yesterday morning all of our fish (2 clowns, 1 royal gama (?), and a lawnmower blennie seemed to all be breathing hard.
Their gills were puffed out as far as they could go and they slowly died, one at a time. 

What's strange is our skunk shrimp and ceramic crab (as well as our zillion hermit crabs) seem unaffected.  The only invertebrates that perpetually die are our snails.

I think it is possible it was gill fluke but how the heck do you test for that and furthermore if it was a parasite what is the chance that if I put more fish in they won;t get infected right away?

What are my next steps?  I was planning on letting the tank run with out fish for a couple of weeks, put in some medicine to kill gill fluke, and change about 20% of the water a week with distilled water versus treated tap water.
My neighbor has a reverse osmosis filter as well he dedicated to our cause.

Any other suggestions?  More so what is the hardiest fish to get that we can use to reintroduce fish into the tank?

[matt]

I'm not into saltwater but from my freshwater experience I can tell you that ammonia and nitrites are bad at any level. These two should definitely be at zero if you are to successfully keep fish.

What are my next steps?   
I was planning on letting the tank run with out fish for a couple of weeks

I would let the tank sit without fish until your cycle is complete. Test the water and and when ammonia and nitrites are at zero then you can slowly start to add new fish.

[Julie]

Hi, sorry for your loss.
Do you know what the ammonia level is?  Ammonia is toxic to fish; and would have caused the difficulty in breathing.
It appears a mini cycle is occuring in your tank.  Do you have live rock in your tank; or what are you using for bacterial filtration? 
Did you add chemicals to treat for the red slime?  Perhaps this is what upset the bacterial balance in the live rock(if that is in your tank) causing your tank to cycle.

[Funkmotor]

Everything seemed fine.  we did some cleaning in the tank and shut it down for the night.

If it was any kind of parasite, you'll want to keep the tank fish-free for 6 weeks at least.  After something like this, I'd say that's not a bad idea anyway.  But it doesn't sound like a parasite.

Ammonia is toxic to fish at almost any level, but in a reef/marine tank is is positively deadly at almost any detectable concentration.  It could be that whatever you added to the tank to kill the red algae killed other beneficial bacteria as well.  I suppose the shortest thing to say is that you're never supposed to add chemicals like that to a reef tank.  (Yes, people do it, but mostly as a last resort.)

The thing about algae problems is that most of them aren't permanent.  They're just part of the ebb and flow of the reef, and you don't need to to anything for them to go away on their own.  Sure, you'll have things related to flow and such, but they're usually solved by tweaking a powerhead (or adding another one) and aren't a sign of impending doom.

I'm curious about the "...and shut it down for the night" comment.  What do you - exactly - mean by that?

pH of 7.9 is a bit low, but probably not enough to kill anything.  I'd be curious to know what your level of nitrites was...(ammonia -> nitrite -> nitrate) if you have a test kit for that.  Nitrate isn't bad at low levels, but ammonia and nitrite are killers.

Also, please fill us in a bit more on the tank.  What sort of filtration is in there, how long as it been running, how much rock, type of sand/substrate, and so forth.  Anything that can help us help you.

[fishdaddy]

sorry for your loss!!
i had the same thing happen to my 120g tank,none of my inverts or any thing was affected.
I lost 7 fish in all 2 fire fish 2 chromis 2 Anthias 1 Dragonets, i was at a loss at what could be happening still don't(know knock on wood all is doing well)i would say to give it 6 to 8 weeks before you put any more fish. I would check all you promoters first then you should move on when all is right.My inverts were doing great and unaffected  so i consecrated on them.as the way of hardy fish clowns in my opinion are the hardiest ones but i am no expert.

                             good luck!!!!!!

[kennyman]

When you do reintroduce fish you might want to reconsider what you feel is an appropriate bioload. We all have different experiences but in my oppinion a pair of the smaller type clowns like Ocellaris is all I would put in a 20. Or one Midas/Bicolor Blenny and one clown. Unless you have a sump of equal or greater size you will be fighting against disease and pollution.

General rules of thumb for stocking fish are always controversial but 1/4 the stocking dencity of FW or 1" of fish per 4 gallons is a good place to start.

[ray]

Did you shut down your pumps for a period of time.It sounds like oxygen starvation.The fish are always the first to go in this situation.
Since your parameters are ok,incl temp,the only other thing could be some toxins in the water.Even if it was some gill related parasite it would be unlikely for all the fish to expire simultaneously.Good luck in the future


Ray

[unshaven]

About 22 lbs of live rock, 2 powerheads, a whisper 20-40 power filter.  By shut down I mean turn off the lights and thats all.  They are on a timer.  The bright white turns off 30 minutes before the blue moon light.   

I was a little premature with the Blennies death.  Looks like eh pulled through.  I had written him off as a loss as he was gasping on the bottom.  We decided to shock the system and did about a 50% water change.  Drastic I know.  But it worked.

Our nitrates were at 2 ppm.  Phosphates at negligible levels.  Like could barely see a hint of blue.  Ammonia was virtually non existent (tube was clear with a slight hint of yellow).

The red slime remover was added about 2 weeks ago and it cycled through without any apparent damage at the time.

We are also going to stop using treated tap water and go solely to distilled water.  That might help.

I thought it might be gill flukes as well.  The symptoms seemed to match.  Can fish pull through gill flukes and live without medication?

Anyways this is the girlfriends tank and I have a freshwater.  I might stick to F.Water.
Mush easier.

Thanks everyone for your feedback.