What would kill fish when corals/inverts are thriving?

Ok, so im just wondering is there any reason why everything in my tank would be doing really really well: Corals, shrimp, snails, starfish, tube worms etc. Basically everything....apart from fish?!?!

In the last few weeks (At seperate times and not added together) i got a black clown, Evansi Anthias, 3 firefish, a twin spot wrasse, a cleaner wrass, a sohal tang and a damsel of some sorts. All pretty small bioload for my big 325g system. They seemed to be doing really well for a few days. Swimming a lot. Eating everything i fed them. Then one morning i would wake up and i would find the fish dead and the shrimp eating them. Some of the fish would go for a week before dying. Some would die the very next day.

Im stumped by this. The chromies and the largish yellow tang in the tank have been doing really well for months (chromies were the first fish in the tank). It just seems the newbies cant adjust very well.

Im not detecting any signs of illness or disease and if it was something to do with my water conditions/parameters then surely the corals/inverts would be popping their clogs first, right?

I did have a theory that it was just the shop i was getting my fish from that was seling me dodgy chinese rip off fish But the 2 latest fish to die were from a different supplier.

 

I noticed in your sig says fish only with fake rock? do you have anytype of filtration? The best kind comes from live rock so you probably do not have have place for bacteria to break down all the waists. Just my 2 cents

 

What are your water params?

 

Yes. There is plenty of filtration. Although most of the display tank consists of fake rock. There is still some live rock in it. Also in the sump there is close to 100lbs of live rock. There is also live rock rubble in another section (a lot). There is 2 large skimmers each rated to 250g each. I also have a refugium that has been up and running for about 3 weeks now.

The fake rock is just to make the display pretty and easy to manage

 

if its only recent additions being affected , it could be water quality issues
residents being expossed to gradual increases in nitrate levels can adapt to them
but new fish introduced to systems where these levels are high can succumb to them

Stray voltage at lower levels could explain fish deaths but no affect on inverts etc
Stray voltage is said to effect the fishes lateral line system - giving them a constant predator alert which if it goes on persistently may stress the fish to an early demise
google stray voltage - there are a lot of links to unexplained fish deaths that stray voltage is considered the potential reason for.

internal parasites / bacterial infection could also be a consideration- no external signs of anything wrong

get a list of your water test results up
at least we can then rule out certain things

Steve

 

Just did a quick test a few minutes ago

Params

Ammonia: 0
Nitrite: 0
Nitrate: 20
ph: 8.2
sg: 1.023

Everything is fine on paper. Was one of the first things i checked after every fish died. But was pretty much the same as the results i got now

 

How are you acclimating your fish? Could they be forced to adapt too quickly which is stressing them?

 

Sh*t! I just googled stray voltage and im no electrician...but it seems like that may be a viable candidate for the problem here. The symptoms are too much of a coincidence. So tomorrow i will go get a grounding probe and see if that helps.

(maybe i should have left the wiring and complicated electrics up to the professionals)

 

Hope you find the cause. Thanks for the params, do you know the extended params like Calcium, Magnesium, Alkalinity, Phosphate?

It's always good to get all the params tested and/or get yourself some test kits so you cover all your bases. I just started dosing and got all the Salifert kits.

best of luck!

 

are the corals doing well or is it FOWFR?

Fish only indicates no coral. But coral doing fine indicate it is not fish only.


I really am confused by your setup.

Any event, I'd want to have a minimum of 300 lbs of real rock in a 325gallon... even if it really were fish only...