125 watt heater on back of AIO

[aMbi]

New reefer here. I have a 125 watt heater in the back of my AIO. I've kept the heater set at 78 degrees. My fish are doing fine and I have zoas, hammers and few LPS that are also doing fine. Tank is 26 gallons. I have been checking water temp with a mercury thermometer that is specifically designed for checking temperatures of liquid dyes for tinting eyeglass lenses. My thermometer is reading 74 degrees bit everything seems to be doing okay. I know I should get something more accurate but cannot at the moment. Is keeping the heater at 78 okay or should I bump it up because it is in the back of the AIO?

 

[Chriokid79]

You should think about getting an inkbird aquarium heat controller. They have been very reliable and accurate for me. Also pretty affordable.

 

[Floyd-]

Agreed on inkbird. I got the one that does heating and cooling for my 25 gallon