Are cannister filters strong enought to drive a UV filter in line with it also?

[pacu mom]

yea, "worked out really well for us" is hard to really gauge...
　
A UV light will "clarify" water at a much higher flow rate than it will kill parasites...
　

This is why UV lights are one of the few areas that I do not suggest taking “user experience” as the strongest guideline.
　
It’s only those cases where we know our fish are vulnerable to parasitic attack that typical user experience can really know if we are killing parasites.

Let me clarify: It worked well for us in controlling green water. You are right--we never cultured the water, so I can't say what micro-organisms were killed.

Before:

With addition of UV sterilizer: