Welcome Dave! Tank looks great. Fill us in on some details....what size tank/sump/equipment, etc.
I'm assuming the $20 skimmer is one of those wood air-stone skimmers. They will work, but you can't use a small $6 air pump to run them....they work when using a higher pressure/high flow expensive air pump. By the time you buy the air pump along with the $20, you could have purchase something like a Tunze. The issue with a Tunze is that you need to make sure you can fit it into the AIO tank. When I had a JBJ 28, I actually had the skimmer in the corner of the DT.
Lots of great color on that rock!