So this has pretty much turned into a DIY skimmer thread, but oh well. Just chalk another one up! Anyways, I finally got the skimmer up and running. I ended up making it an in-sump skimmer. This solved a few problems:
1) The outlet pipe took a lot of work to get water-tight and I still didn't trust it.
2) Due to the outlet pipe needing to be high enough to get over the edge of the sump, it made a lot of gurgling sound trying to exchange air in the tube so the water could flow down. I lowered the outlet to below the water level and now it's completely silent (minus the pumps).
3) For my tank size, I need about 22.5 gph of flow through the chamber. That's quite low. After lowering the outlet pipe, it makes my pump (Rio 800) work much harder to maintain the appropriate water level in the chamber and it really slows down the water flow.
Having said that, I'm not sure what the flow rate is. My pump, with the fixtures and horizontal pipe length, was calculated to be pushing 167 gph. That's WAY too much. I thought about measuring the flow rate in the bath tub but freshwater has a different specific gravity and it wouldn't be accurate. If anyone has a way to figure out how to measure that, minus filling the tub with saltwater, then please let me know!
So, as far as the ceramic air stone, I think it's going to do a wonderful job. I noticed about a 4" jump between the water level and then the bubble level once I plugged in the air pump. The PVC is white so I can't see inside the chamber but I know it's probably a typhoon of bubbles in there. Just from seeing the stone in action while just thrown in the tank, I'm convinced. I can only imagine what it's like in a confined place. Anyways, if anyone wants some blue prints, parts/price list, or instructions on how to build it then let me know! Hopefully this skimmer lives up to my expectations. I have a lot of confidence that it will.