Sudden Fish Loss!

[ang_99]

Yesterday I experienced sudden fish loss which freaked me out. My system has been up and running for 3 years with no major problems.

46 Gallon
About 70 pounds live rock
5-6 inch fine sand bed
AquaC HOT skimmer
Magnum 350 canister (for Carbon and Mech. filt.)
A couple power heads
Medusa Temp controller (hooked to small fan and heater)
Ground probe



Live stock:
Regal Tang (I know, too small a tank but didn't do my homework when I first bought him)
2 Ocellaris Clowns
1 Chromis

Coral:
Bubble, Candy Cane

Yellow polyps, and a few mushrooms.

4 Turbo Snails

Have not done any tests in a while, SG 1.026

I am currently going through a cyano out break and got lazy the past week or so and let it build
up on the glass. I used the Magnet and cleaned off most of it from the glass, of course there was a ton of it
floating around the tank so I reached my hand in and took the screen off the canister filter intake so it doesn't get
clogged and it can suck up the floating blue-green algae. About a half hour later I glanced at the tank and noticed
the chromis was dead and the other 3 fish were gasping like crazy. The clownfish were on the bottom gasping
and having trouble staying upright, the tang was gasping also but seemed to be handling a bit better (I guess because he
is a lot bigger), The star fish then ate the dead chromis. I had no reserve saltwater so I hurried and mixed a batch of fresh
saltwater, (obviously you are supposed to let it mix for a couple days in normal situations) the salinity was a bit off cause it was the
last of it (about 1.023), I put the worst of the clownfish in there but he didn't last long and died. I then put a fresh batch of Carbon in the canister filter and
let the remaining 2 fish stay in the tank. The 2nd small clownfish died overnight I think. I believe the starfish ate him too because the central disk was a big bulge this
morning . The Regal Tang seems kind of OK, it looks pretty lethargic but I put a few flakes in this morning and it did eat. Also he is not gasping
like crazy anymore.


The coral and polyps seem to be ok, they extended there tentacles last night to go into feeding mode. The star fish is fine I assume, especiallysince it ate 2 fish.

I did do an ammonia test this morning and results showed no ammonia (old salifert test kit though not sure how accurate it is anymore). So could have the tons of cyano
floating around have caused the sudden fish loss? I don't think it was me putting my arm in the water, I don't recall handling any chemicals or anything that would be
toxic. I am at a total loss here. There is also a couple calupra (I believe) stalks growing not sure if that could be hazardous in any way. I do have a small toadstool mushroom
that is being taken over by blue green algae, could it have released some kind of poison? The system has been running just fine for 3 years and all of a sudden this happens and
I have no idea why. Its kind of discouraging, I wanted to replace with a bigger tank at some point but am now re-thinking that idea. So any ideas?

Thanks.

[DHarms]

I'd have to say something bad on your hands.

[outprowllin]

id suspect a loss of oxygen . what temp was the tank and was there a large amount of cyno floating around the tank? the sand bed may have been releasing a lot of co2 and that combined with a lot of cyno floating around . you may have exausted the o2 levals. was the water temp high?...there are so many variables it will be very hard to pinpoint a solution at this point. all you can do it post some info and maybe we can come up with a list of probable causes.....

[ang_99]

DHarms, although possible I find it highly unlikely. I just simply dont recall handling anything detrimental to the tank.


outprowlin, interesting. The tank temp at the time was about
82F. Its been really hot around here. Yes there was a large amount of cyano floating around for a while until it was sucked into the canister filter which took about 15-20 minutes or so.

BTW my Regal Tang seems to be back to normal at this point, he is back to eating and swimming like his usual self. Only fish left

[outprowllin]

was your canister filter running up until the point of trouble or did you turn it on when you started to clean up the cyno. and if so. if the canister was started at the time just before trouble, was it filled with tank water from an other time? does that make sence?

[ang_99]

outprowlin, yes the canister was running the entire time. I understand what your saying. The canister is always running so the water comming out of it was not "stale"