Hi guys,

I need to know how my guppies will fair in elevated temperatures. I have a heater that keeps the tank at 77F (25C) ; but a recent heatwave caused the water to elevate up to 86F (30C)! :o

I cut back on the lighting and the heat wave has subsided; but the water is still hovering around 82F (28C). I am kinda at a lost on what to do now, any suggestions? :unsure:

I had a similar problem a while ago, it sounds silly and obvious, but the only sollution I could find was to do a 30 percent water change, and top up with ice.
28` celcius is not that warm though, I'm into goldfish currently, but my friends' tropical tank runs at those temp normally, no problem.

Guppies may be stressed over 80 degrees F. Doing a water change with cooler water is the best thing. If you have city water (or even well water), you probably don't want to add ice directly to the tank. Remember it will add chlorine (and freezer ice maker contaminants). You can put ice cubes in a ziploc bag and float it on the surface. If you can't run an air conditioner in the room, then you should shut off the lights (which generate some heat) as you did. You can run a fan over the surface of the water. This, of course, requires removing the lid which can result in fish jumping out. Since warmer water holds less oxygen, aeration is extra important in hot weather. I suggest setting the heater to 75 degrees F for guppies (and one pleco, right?). If there's any concern that the heater is not functioning properly, just unplug it during the hot weather so it doesn't add even more heat by accident.