Help!!! Fish dieing rappidly

[Lifeguard50020042005]

ok so i have a 75 gallon tank in which is about 6 months old and all of a sudden my fish are dropping like flies. Every night i lose one more. Originalyy in my tank i had 2 tomato clownsand 2 lawnmowers. The other day i went out and bought, 7 baby green cromises, 2 false preculas, and 2 dimon gobies. I now have 1 tomato clown, 2 green cromises, 1 lawnmower, 1 precula, and 1 dimon gobie. The water peramitors all tested fine, and the fish all looked healthy and it just seems that the next day there is one less, and i see my hermets making a meal out of the dead fish. Now this morining i noticed on the 2 chromises that they have chunks missing out of their sides like they have been being eaten alive!!! what is going on? does anyone have any ideas?

[jojo22]

Could you have a mantis shrimp in your tank??? Do you cever hear a clicking or pounding sound??

[Lifeguard50020042005]

i dont think i could have any mantis shrimp because everything in this tank was brought over from my 45 gallon and i never had any problems with it. I never hear any clicking or pounding, but i did notice that this morning they left parts of the fish behind like they were full. Could my hermits be attacking my fish?

[jojo22]

What does you whole clean up crew consist of. You obviously have some type of predator on your hands so it is only a process of elimination.

[Lifeguard50020042005]

well i have a 75 gallon tank, my clean up crew consisted of 2 lawnmowers, 2 dimonds, 30 hermits, 30 turbo snails, and 2 of thos white 1 eyes snails that burrow in the sand

[jojo22]

What type of hermits???

[Lifeguard50020042005]

I just lost another one!!!! i just waled in here to write back and i walk back out and he is covered in hermets!!!!! i have red legged hermets that i have had in my tank for quiet a long time.

[jojo22]

How old are your test kits and what brand are they.

[graphixx]

it could be the hermits but I dont think they would be quick or agressive enough to hunt and catch fish. but I would not be suprised. I would go along with a mantis or a type of gorilla crab. there is definately some sort of predation going on in the tank. you could have a mantis in there for months and not know its in there

[jojo22]

That is my line of thinking I just wanted to ask about the test kits to make sure it isn't a water problem and the hermits are just doing their job.

[bobert]

maybe one of the fish is attacking the others

[greg97527]

Not to burst your bubble but i will put money on the lawnmower blenny, especially if ur diamond goby's are dying. i tried to put a lawnmower in with my diamond and in a split second BAM he was on the goby like stink on **** lol. also only 1 diamond per tank and same goes for lawnmowers.
i have heard of others having success but i personally have never been able to keep more than 1 of either the lawnmower or the diamond goby and its one or the other.

[jojo22]

good call!! does the lawnmower show any aggression???

[hummer]

aw...sorry too hear about your loss ... hope you can find the problem