Temp Swings

[anodized]

the temp in my community tank goes from 72 at night (heater minimum) to 81 or 82'F through the day. the tank has an open top with a 4x65W CF light. the substrate is dark and might be contributing as well as a lot of plants in the tank

is this temperature swing too much? the fish seem fine i just wonder if there would be a simple way to keep it regulated between 72 and 75 degrees, or what my options might be

 

[*Fishkies*]

I would try keeping the heater at 78F to 76F degrees. If it raises higher during the day that is fine. As long as there is no more then a 4F degree change I would not worry about the temperature fluctuations. However you are having temperature fluctuations of 10F degrees. Temperature changes that rapid, can often stress fish out and cause diseases.

What type of heater do you have?

 

[anodized]

its a hydor external 200w

i'll try raising the temp to 75 and keep an eye on it to see if it creeps any higher than 81