Why did 3 fish just die in a week and a half?

CURRENT Livestock:
2 Clown Tangs
1 Pepermint shrimp
1 Fire Shrimp
30-40? Assorted inverts (turbosm, nassaris, hermits, ceriths, nertile)
1 Clown tang
1 Frog Coral or Hamer coral, cant remember which

First my gf bought a baby hippo tang who was on the fritz ever since she brought him home. Hiding in rocks etc, and it looked like he had the ich, but just mildly. He died a about a week and a half after we bought him. All watter parameters were fine, 0 across th board. I replaced him with a clown tang and a diamond goby. Everbody was fine with the new fish and no flucuations in params. A few days after I add the clown and goby, I find my scooter blenny dead. No signs of a strugle... Take him out, thinking he might of diead for lack of pods.

TODAY... I find my new diamon goby dead. I JUST checked my water again and EVERYTHING is fine! I'm using a Saltwater Master liquid test kit. My frog coral doesnt look as healthy as it usually does, looks a bit shrunken in. What could be going on? I would hate for my clown fish to die. Hes my fave so far. And I feed the tank spirunela (sp?) but he barely eats it. The clowns gobble it up!

 

What size tank?
Was there any bullies?
What about the bodies, where they.. Complete?

 

I'm assuming that this is in your 46 g bow front? What are your current parameters, and ranges between extremes of temp and pH (if you know them)?

 

Yea, 46 bow, PH is at about 8.0... looking at the test kit, but i tested like 45 mins ago, i dont know if that was the reading then. the color might have changed?

the water is usualy between 75-82 degrees... no bullies. i find the bodis NOT in tactt, but i think its because of the clean up crew. when the tang died, there was barely a trace of him except a yellowish tail. the scooter had half his body torn open, and the goby had a big hole in him... but there were critters and worms on him.

 

I'm thinking you have a Sometype of hitchhiker. Mantis shrimp comes into mind.

Try looking for one at night, use a red-light.
What about lack of oxygen?

And for future reference, your tank is too small for any tangs.

 

Nitrates?

 

everything was @ 0. Mantis shrimp? Wouldnt it have killed my clowns or dragon shrimp already? They were in the tank for WAY longer. The most recent hitchhiker I found was @ peanutworm. I have been trying to find other hitchhikers @ night but never see anything.

Also, what does a dead snail look like? I seen things that look like SNOT from time to time, could it be dead snails? Maybe I do have something killing and eating my fishies?

 

Wow, that's some temp swing. Might want to look into that.

 

I think you need to do alot of research and leave your tank empty for a long time. You had 2 fish that grow to be 15" in a 36" tank? At what point did you think this was a good idea? You also added alot of fish quickly, how old is the tank, how old are the test kits, did you have someone check independently? When you say all parameters does that mean Ca, Alk, Mg, NO3, NO2, PO4, as well as ammonia? Are you dosing anything?

 

Ouch