I 've never looked into combo filters, but I have to have a uv filter,
otherwise I'm looking at pea soup the whole season in my pond. Granted, my
fish stock is higher then it should probably be, and because of that, they
wreak havock on my plants, so getting 40% coverage alays seems unobtainable
to me.

I live in an area where getting pond plants locally is difficult, and
shipping them have been a very mixed bag.

I prefer natural methods if possible, but I'm very happy with the
cost/performance that I've gotten from adding a uv filter, though it took a
while to get everything set up properly.

--
Gareee
(Gary Tabar Jr.)