Temperature -- I think I blew it

[anchor10]

Long story short -- we let the house cool off last night during the first cool evening of fall. Temp in the house had been regulating tank at room temperature. So the tank got down to about 70 degrees last night. It's typically 78-82. My clown fish died, my yellow tang will be dead in an hour -- and my sailfin is covered in what looks like velvet. All other water paramerters are "normal" slightly elevated nitrate and phosphate -- but not out of the ordinary. Other fish and organizms are fine. Did Temperature do in my fish?

[Percula9]

Temp killed your fish. Why wasn't there a heater in the tank? You never ever let air temp regulate water temp. Sorry for your loss. Put a heater in there asap.

[anchor10]

The heater is in there. I had unplugged it when I was doing some work. Took my eye off the ball. The sailfin Tang is eating and active... Temperature is back where it's supposed to be. Think it will be ok?

[Percula9]

I guess you learned your lesson. Good luck in the future.

[anchor10]

Yeah. Thanks. Although it was a mistake -- I'm still surprised that a temp swing that small could cause so much damage!

[Percula9]

From 78-82 to 70 is not a small temp change for the fish. It causes a huge amount of stress, and this makes them succeptible to illness.

[anchor10]

Thanks for the help. Tough lesson!