Ok so im looking for an in tank self suffecient UV sterilizor. I have greenish water that i CANT get rid of ive tried everything. I dont want to have to go buy a power head aswell so is there uv sterilizors that have their own pumps they I can stick in my tank plug in and leave ? What wattage is best for a 180 ? Last question are thies things a one time use kind of deal or do you just put em in and turn them on when needed then store away? Or do you plug them in and leave them in the system ? Im a little confused about them but I think they can solve my green water problem