Sorry this took so long...
OK, by far the most effective mod is the air stone/pump mod which just so happens to be what I have running. All you do is drill a hole in the center of the lid for an air line coupling. Using a small piece of airline connect a 13.5" length of rigid airline and then another small piece of airline to a Red Sea Limewood air stone. That is the important part! I haven't found another brand that will fit so to my knowledge it *must* be the Red Sea one. This goes down the small center tube. Then replace the pump with something in the 80-100GPH range, adjustable would be better. lol, I don't even remember the brand I'm using but it was a cheap Chinese import, cost me $12 I think. So far as an air pump, right now I'm testing a corallife Luft (not as impressed with it actually) but I was running the largest marineland air pump for a long time. I ran both outputs (wide open) into a gang valve. One GV outlet into the skimmer and one to another short length that has an old used air stone on it. The old air stone acts like a muffler for the air you bleed off and you use that valve to control how much air goes to the skimmer. The less back pressure you put on an air pump the longer it will last so bleeding excess is better than throttling back. Plus it allows better precision.
Now there is another "mod" I'm using... If you do some looking it's called a foam gasket mod. In my case it's actually an accidental silicone gasket but whatever
. It's a really long story involving a mod that isn't as effective so I won't bother going into it. Either way what you can do to try it out is wrap the collection cup with Teflon tape where it seats into the intermediate tube (the removable one).
So really, all this will make it a passable skimmer... I've made better skimmers on the kitchen table! So if it is a reef, listen to Lorna and get a better skimmer
. What I'm saying though is if you are thinking of going skimmerless... try this instead!
May as well use what you have.
So far as the UV and canister. I'll second that you should look at alternate filtration. *IF* your tank is a reef, it's too small to run a UV IMO. And no matter how you cut it, the canister would be extremely labour intensive to maintain. Anything it catches still breaks down (rots) which add nutrients to the water. You would have to do maintenance way too often for my tastes to keep up... say once a week as a ballpark figure? Maybe more...
Chris