Fish Keep Dying

[aliorca]

I woke up this morning to find three fish, one clownfish, a fairy wrass and a goby dead. All my levels are good, the fish don't have any white spots on them. I also lost a clownfish earlier this week. I have no idea what is wrong with my tank. I change 20 percent of the water every other week, my protein skimmer works great. I now have one clown fish, a cleaner shrimp, a yellow tang and a regal tang left in the tank and they are all acting normal. Does anyone have an idea what could be going on. Thanks

 

[lewiss]

Loads of things could be!? What are your levels? Ammonia, nitrate, nitrite, PH, salt? Do you add anything to the water??
Do you have powerheads are they pointing at the top, moving the water?

How longs it been set up, how much live rock, do you skim? Do you have a filter running? Wht do you test with?

 

[Donya]

The shrimp would normally be a bit of a canary for water quality, but still, the levels being "good" doesn't really tell us much. In addition to lewiss's questions (exact numbers from your test kits, type/brand of kits, water additions, pumps and other equipment aside from skimmer, etc.), I would like to add a few more in case the water checks out:
- What size tank?
- How long has it been running?
- What type(s) of clownfish?
- Prior to death and after death, were there any marks or other signs of physical damage to the fish?
- Were the fish eating well/acting normal leading up to death?
- Any other invertebrates in the tank?
- Any changes to the tank's equipment, stocking, or maintenance routine in the last few weeks?

It may seem like a lot of irrelevant questions, but with so little to go on it will help get to an answer fastest with all bases covered.