How cold is too cold?

[Goldstripe]

This morning I when I looked at my tank I noticed that my sump level was a bit high which was a little weird because I knew I needed to add some topoff. Looked at my return pump and it wasn't pumping! I have a temp controller in the sump and because water wasn't flowing through it was heating up from the skimmer pump which in turn, kept the fans blowing on the display. I'm not sure how long the pump hasn't been running but I'd suspect about 2 days. Everything appears to be okay except for my largest blue tipped acro colony which appears to be losing it's color. Once I took the bad pump out and put a backup in place the temp controller was reading 76!! Is that too cold or borderline?

Also wasn't skimming the water for the same amount of time because there was no flow into the sump.

[Fly Guy]

If you typically keep your water at say....80......and have SPS, that can be really hard on them, and if it happens on a regular basis can contribute to their eventual decline and death. Dropping 4 degrees for softies and LPS although not ideal, really isnt a big deal IME.

I just 2 days ago had my lps tank drop to 73 becasue i was messing with the sump and forgot to plug the heater back in AND left the window open all night............

THATS too cold but it was an isolated thing and wont hurt anything in THAT tank

[Goldstripe]

Thanks for the response Fly Guy. I actually keep the tank temp at 79 so that would have been a 3-4 degree drop for them. One of the SPS looks stressed so I hope it doesn't croak, it's one of my favorites. I just did a 10 gallon water change (65 gallon tank) and will do another one tomorrow and hopefully everything will perk back up.

I WISH I could leave my windows open and have the temp in the house drop like that, lol. It's 100 degrees outside, well ok maybe 98. Go away summer!

[Wiskey]

I keep my tank at 80 because I don't have a chiller, but some people run their tanks at 75 all the time. I don't think this is too cold, but the lack of skimming for a couple of days and the change in flow could have been the thing to annoy your acro.

Whiskey

[Goldstripe]

Update: I did lose my largest acro colony. It was a blue tipped variety of some sort. My blue tort was also rapidly losing color from the base up so I fragged it last night and hopefully the piece will live. Very upsetting that I just lost $200 worth of acros