Hello; reduce light period is my #1 suggestion. Six hours may do it. If not even shorter.
I do not think plecos will help at all.
No idea at all as to how UV will help.
Since algae and other plants use nitrates a heavy WC schedule may help by keeping the nitrates down.
Reduce feeding of the fish a lot.
Make an algae scrubber.
Not sure if this helps with algae but adding good bacteria and enzymes ( such as in RID-X) may be worth a check. Several threads on this in this forum. I have tried it a little. Dod a search for RID-X or for maybe probiotics.
My crawfish seem to do a pretty good job on my white crushed shells. Careful if you have fish that like to sit near the bottom though. They will grab them at times.
If you're not keeping live plants then I recommend leaving the lights off completely, unless you are feeding or observing the tank. I do this with my 220 and it has no algae at all.