Healthy firefish died over night :(

[Grebex11]

Hey guys,

I've had a firefish for exactly two months. It's been eating every day. I do a mixture of mysis, pellets, and flake. It even ate yesterday and then when I look at the tank this morning, dead. From everything I could tell he was perfectly healthy before turning up dead.

Only one other fish in the tank, a YWG I've had for 7 months. He appears to be fine.

This is a 15g mixed reef. Only changes I've made to the tank in the last week: added a green toadstool coral and a devils hand leather on Monday (4 days ago). I know these can release toxins but I've never had any issues with them before. Seems unlikely. I also started using some GFO on Sunday. Again, not something that could cause this.

Oh, one other thing I don't typically do but have done once before. I was in a bind an used distilled water for top off instead of RO from my LFS. Again, I've done this before and have gone through the forums of people saying it's fine. But that is also something different I've done in the last week.

Any ideas of something I could have done?

 

[Sharkbait19]

Same here! I had one completely healthy, eating, swimming, very active. Next morning, crabs were walking over its dead corpse. I blame my feisty emerald crab but also suspect something odd happened. A mystery to this day for me.

 

[Grebex11]

Same here! I had one completely healthy, eating, swimming, very active. Next morning, crabs were walking over its dead corpse. I blame my feisty emerald crab but also suspect something odd happened. A mystery to this day for me.

So weird! I have nothing that could have attacked it. 2 hermits from a previous tank but that's really it for inverts. No way I have a mantis or anything. Tank is way too small to have a hidden critter.

 

[Andreas' Reef]

Same, I had a purple one the bit the dust, and I think it's because my clown is a pig at feeding time and will eat all the food in 20 seconds.

 

[Grebex11]

Same, I had a purple one the bit the dust, and I think it's because my clown is a pig at feeding time and will eat all the food in 20 seconds.

So weird. I guess a lot of people have had this happen. This was a helfrichi :mad:

 

[Sharkbait19]

Mine was a red.
Maybe there is a dietary correlation to their deaths. Mine grazed on pods and readily ate prepared foods, but maybe that wasn’t enough?