Tough to say. I was wondering if they're magnetic or electronic. I didn't know if you were considering switching your fixtures to DE bulbs or if you just wanted a different type of SE bulb. The only SE bulbs I've used are Hamiliton 400w 10k and 20k. The 20k are really blue, which I like, and I had decent growth with them as well. This was run on an Icecap electronic ballast.