I found that I had problems having 1 of the biotek's on the same ballast as a regular t5. after a couple days, neither would work. Feedback I got was that mixing on the same ballast may be a no-no. So, I went with 2 of them on the 2 light channel 1 ballast of my 6 bulb ATI ... which was a great look for dawn and dusk with coral pop. But, the PAR drop was drastic with all 6 bulbs on. So, Ive pulled them and am still in the market for supplemental LED lighting...