Everything dies except blue damsel

I have a 55g with LR and a few inverts for cleaning. Over the last 8 months I have introduced a variety of fish, only to have all die, except this blue damsel which I have now had for 6 months. I've tried QT and doses of formalin, malachite green, Rid-ick, osmosis shock, but one by one they start their own private party in the corner and are rigered shortly after.

Water params are fine, no ammonia, nitrate, nitrites, etc. SG 1.023.

The only fish that has survived it all and been through all the treatments is the blue damsel. The inverts seem unaffected by whatever is the issue. I have not seen white spots, black spots, protruding scales, bloating. They swim normally and eat normally, but just within 24-72 hours of changing behavior they will crash and die.

Any ideas?

 

How long are they in your tank before they die?

Are you buying all of them from the same vendor?

Just a couple of questions

 

were are you getting your fish? are you acclimating your fish, if you ordered them from online then they have to be acclimated to the websites instructions. if they are coming from a fish store i would be wondering if its the fish store.

 

hard to say but i would try getting fish from a different pet store if your water is up to snuff, there is a store near me that is a good store but every fish i've bought there has died in a week while all the corals i get ther flourish, i dont understand why but the store on the other end of town is horrible with a capital H yet every fish i've bought there does extremely well for me while all the corals have perished. i just accept it since trying to figure out exactly why just raises more ?'s

 

I get the fish from my local Petco. Unfortunately I had a bad experience at the non-chain FS so I don't use them. Petco is really my only local option.

They all perish +2 weeks out. I am drip acclimating them for 1-1.5 hours until the parameters are equalized.

 

i would also question the amount of time they are acclimated.
EDIT: just saw your answer

what are the ways your system replenishes oxygen?

who tests your water? normally those who test their own will not say "my water params are fine" we will give more accurate numbers.

damsels are tough fish. have you ever seen any bullying behaviour?

answer as many questions u can from the 3reefers, im sure something will come up.

And WELCOME TO 3REEF!!!!

 

Do you have or know someone with a multi meter? It might not be a bad idea to check for any stray voltage in the tank. How is your surface agitation and how big is your skimmer? Could also be a lack of oxygen.

~Will.

 

what inverts do u have ? mabe a preditor invert is stressing them?

 

The inverts are a few hermit crabs and snails. One hermit is quite large, maybe a 3 inch shell. But fish were dying before he arrived. Those are the ones I know about, I haven't seen anything suspicious or unidentified.

I use a 10g sump with a 1350 gph pump which stirs the main tank by moving water across near the surface and down, swirling back up to the tank top. So there is side stirring and bottom to top stirring action. The sump has a skimmer with a 300gph pump, seems effective. Also a foam filter and biofilter and refugium area. The sump weirs cycle the water top to bottom in the sump and cascade down to the pump, which adds to the agitation. The sump siphons water from an overflow box that skims the display tank top.

I assume if there was insufficient O2 then the other life would also perish. Could the water current be too much? It is strong in areas of the tank.

I don't know about the damsel bullying. I tried two tangs, a yellow and powder brown, which were much bigger than the damsel, and they both recently perished a week apart.

 

Tangs are far more demanding on O2 levels than a damsel or your inverts. I would add in a couple powerheads (at least Koralia 3's or MJ900's) and make sure they stir the surface more than it already is. Also a 55 is kinda tight for even the smaller tangs, I would recommend looking for fish more suited to a tank that size.

~Will.