If you head over to RC, there's a VERY LONG thread on T5HO Q&A, by Grimreefer, the KNOW ALL when it comes to T5HO lighting. Somewhere in that thread, he compared the two, expecting them to be close to equal. He was very surprised to find the the Tek5 really was quite a bit better than the AquaMedic. If I remember right, he figured it must be due to the different ballasts.