Hi Andy,i can only second what james has said,you saw it in my setup last week and it does well and i dont do anything special,it has 2 54w tubes for eight hrs + a boost of another 2 54w tubes for 1 1/2 hrs,it gets lots of co2 plus easy carbo and thats it,since the cold weather i have been doing water changes every 6 weeks with no noticable differance to plants and fish,obviously the size of the tank makes thing very stable,
regards john,