Theres alot of online stores that carry bulbs and ballasts if you need one. Just google what kind of bulb it is. I take it you got this used?
I really don't think you need a halide on such a small tank unless you wanna keep clams or some higher light sps.
I don't think using just water from a tank helps with the cycle much either if any. You need live rock thats cured so it already has the good bacteria in it and not any die off.
I started my 12 gal aquapod with all live rock and sand from my 150 and it never cycled at all. You have to have enough rock though and it could still do a small cycle. Test it to be sure.
You might wanna start with rock and sand from your 75 and replace that tank with some new rock.
You need about 25 lbs though which is quite a bit.
Alot of people ditch the sponge in the first chamber I kept mine but rinse it good every week with my old water from a water change. My tank is only 2 months old but 0 nitrates so far so I'll see how it does.
I only run chemi-pure in the back and have my heater back there.
I don't use the media that came with it or bio balls.
I also put a hydorflo on mine for better circulation.
The bulbs should say on them what they are. I would just replace them and see if they work.
If you decide seahorses do alot of research first as they arent easy to keep. Too bad cuz we all love them.
This is my tank at 6 weeks. Most of the corals came from my 55 gallon and I kept testing to be sure it wasnt going to cycle.
I just added a few frags every few days after it showed no sign of cycling after 2 weeks.
kass