Water temp matching

[Potluck]

So today I was doing my tanks the first 2 went smooth , I rested for 30 min before i did the third which just has one convict in a 30 gallon (probably to small im sure but it's the tank I took over from my nephew due to not taking care of it) so I siphoned 30% out temp matched the water but somewhere from setting the tap to filling the bucket the handle got moved a bit so it was no longer temp matched it was 2 degrees lower, will this kill the fish? I do have a heater in the tank and a thermometer, I read that 4 degrees lower or higher is the concern.

[Anna94]

That happened with me during my last water change. The water going in brought the temp down to 74, but the heater is set at 78. The heater did its job and all my fish survived. They didn't seem affected by the temp change.

[SherLar]

A small temp change may stress your fish, but shouldn't kill any. A 30% water change, even with adding water 2 degrees won't change your water temp that much. Most fish, cichlids included, have a normal range of temps in which they are comfortable, but getting out of the range, unless it's an extreme variation, won't hurt them short term. And, cichlids in general are pretty hardy fish, especially New World cichlids. I'm sure your convict will be fine.