Not exactly, but if it's set up in the way I suspect (like a Rekord 60 which I have owned) I've had the same problem. Does it have a fixed black plastic rim, a central section of the roof where the ballast and lights sit and then two side slats for access? If not then the rest of this post won't be very useful.
If so it's very similar to my Fluval Roma 125. It came with 2x25w T8s which weren't enough for me. I found the awkward shape of the rim meant you couldn't get a luminaire to fit on it and where it's located in the house meant I couldn't hang a pendant above it.
Solution was suggested by Greg at ADC - an Arcadia ballast connected to two T5s. Ballast is external and the lights fit in to two clips which you glue to the two slats on the hood with aquarium silicone glue.
Not ideal as the wiring is awkward but the best solution I could come up with. Hope that's useful.
