Thanks Guys! Since spring time is here I think it's time to start adding more bio on each tank. It was 32 deg f this morning but I think it is the end of the cold season. The owner/manufacturer of the bio station I get my bio from said to use b50 to b75 till it warms up. I hear about guys using b100 in cold climates year round and I was just wondering how they do it or if they are just full of it.