Heater ?

[jrein8383]

How many watts per gallon should I use. I am going to be getting a 210 Gallon AGA. I have one 100Watt and another 250 watt heater from a previous tank. Will the 250 Watt be enough? Or both? Or just one larger heater?

[MCary]

I think that depends on the temperature swings. My tank for instance gets hot during the day because of my metal halides. My controller turns on a fan that keep them temp about 82 degrees. I don't want a huge temperature swing so I have a 250 watt heater come on if the tank cools to 79 during the night. So my heater only needs to keep a tank warm, not necessarily warm a tank up. My tank is 150 gallons.

[stkitts]

I keep 2 heaters. One set to 80 an one set to 79. I have them plugged into 2 different GFI circuits. If one fails, I have a back up.

[woodstock '69]

I read on RC this am that you generally need 2wpg to raise the temperature 5 degrees above the ambient temp.

So I guess if you have a 100g tank and a room temp of 70 and you wish to raise the tank temp to 80 you would need 400 watts.

100g x 4 wpg (2wpg per 5 degree rise x 2) for a 10 degree rise = 400watts.

I think that is how it works

Michael

[meco65]

I had a 10gal fresh tank with a 20watt heater at my old house and could not move the tank all last winter do to where I was liveing. The house had no heat in it and the temp got down in the 20s a few nights. I was able to get the tank moved to my new house this spring and I did not lose any fish and the tank temp stayed in the safe range all winter long as I had to feed the tank a few times a week I wa sable to keep a eye on it.