The lighting is a 24 inch floresent bulb. It came with the tank. no, i have not checked the tds of the water. i'm not sure what kind of water purifier it is, i know it has 4 or 5 different cyllinders it goes through. i'm using a reeflife liquid test kit for the calcium, alk, nitrate and nitrite. i believe the supplements are kent and aquachem. i have not added anything other than the trace elements, and i add it according to the directions. my problems arised when i cleaned out my filters in my sump. spiked everything.