LF 25-40 Watt UV (Aqua UV, Pentair, Etc.)

[Ritteri]

You might want to rethink the idea of a compact version. They will run hotter (warming the water) and it limits the efficiency of exposure time with a shorter run. People also pipe them vertically with success.
I have one that needs the order of a new bulb and ballast. (Black model) Looking for $100. Bulb is $80 and Ballast was $239 or was it $139 cant remember... at JL Aquatics... But then your still not paying $500+ for a new one.