I saw one of these preskimmers at the aquaticlife swap meet. I think it was in the $10 bin.
I have one of those though. Very nice, but it's a big box. I guess its letting the micro bubbles dissolve on the outflow.
Are there more annual equipment swap meets in the area? I need a bunch of junk like things. Ie bulkhead fittings. Cheap pumps to move water around. Small sump. Etc