In series? I run one on my fx5 for a 100 gallon tank and it works like a champ solid 78 degrees 7 days a week, doesnt seem to come on very often either 300 watts inline is alot of heat. The fx5 is wide open too.
29g Tetra Tank
100g Planted Angel/Clown Loach
I can't spell...Im an engineer, I do math