Hi Frank
In the fry tank,it had no light in has such,it is sat on the kitchen table,so just normal daylight during the day.
Hi Harlequins
Is the temperature in their tanks stable? I have some tanks in my kitchen too and have noticed that the room heats up when I'm cooking. With an electric stove the burners throw heat even after they are turned off so I always have to use the exhaust fan even if it's just to boil a cup of water for coffee. I've had to move the fry out of there while I was doing some Christmas baking to avoid overheating them.