any ideas fish dying

[160g]

ok i have had my tank set up for about a month i have about 40 lbs of live rock and 100 lbs from marco rock in my tank all the levels of the water are normal nirate nitrite copper ammonia gh ph salinity everything i have 3 hermit crabs doing just fine but now all of my chromas have disappeared i had 5 found no bodies just gone over night or while i was at work fed 2-3 times a day i have a friend who knows alot about this stuff and has helped me thus far but we are both baffled about whats happning and i do not want to introduce any more fish till i figure out whats wrong do any one have any ideas thank you in advance

[an411]

maybe a nocturnal hitchhiker munching

[Toddrtrex]

[welcome]

While it could be a hitchhiker it would be nice to see actual numbers for your water parameters. After only a month the cycle might not be all the way finished.

[taillonjohn]

do you have a test kit? 5 fish in one month (the first month of your tank) you probably overloaded your biofilter. this is your tanks way of saying "no, slow down"

[Racing1]

agree that posting tank parameter's will help in finding your problem. Also, are you finding the dead fish or do they just disappear ? If disappearing I would look around the tank and if no bodies suspect a hungry hitchhiker somwhere. Check your tank at night with a red light and look for any crabs or other possible hitchhiker's. Keep us posted as to what you find.

[160g]

i really dont think that there is any hitchhikers because all of the rock was in a friends tank and kept in 5 gallon buskets with powerheads for a while also i took all the rock out when i got the new rock from marco rocks and did not see anything i just took a sample of water to local shop numbers are ok not great by him and my test kit he said he dosent know why htey are dying other than the tank is new and for the size it might not have enough bacteria in it so i got some bio balls put them in the sump and have them above the water live and the overflow goes over them so im going to go back to the shop and get the water tested by them agian next wensday

[Mavrk]

Don't use the bioballs. The rock and sand will provide places for the bacteria. Bioballs tend to make it difficult to keep nitrate low.

Chromis can fight with each other, but since it was all at once, I would bet they got ammonia poisoning. This might have been cycled out by the time you got your water tested.

Have you noticed any gasping? Any other signs of stress? Were they eating. How long were they in the tank?

You don't always find bodies. They get eaten by the crabs and other critters. Probably lodged under some rock.

I have also had chromis jump when they were fighting. I had 2, added 3 more. One was killed, another jumped into the overflow and died a few days later (he was beaten up a bit). Check the floor.

Are your nitrites and ammonia at 0?

[Scoobaman17]

How much surface movement do you have through the system? I had a tank once that had some of these problems "damsels died, crabs fine" but it was because there was not enough surface movement to cycle air into the water. Thanks to RC I fixed it quick. But I do have to agree with the above, 5 fish in the first month is stretching it. I normally wait 1 1/2 months before adding a small cleanup crew let alone a bunch of fish.

[coast2coast7390]

tank not cycled long enough and prolly bristle worms that cleaned them up AFTER they died
ive had a 8 inch fish disappear and taken care of by my cleaning crew before the body rotted