Well I know MH do put off radiation. it is small but having a fish tank near my bed and my 4 year old son, it doesn't make me sleep well knowing that there is cancer causing radiation a few feet from my head. As for thT-5, I haven't used them yet,I won this set up on ebay and today I won a 265 watt power compact. Oh yeah to find out about radiation from MH call any of your electricions . that is why there is a warning with using any kind of MH bulb