nice find...all you need now is a pump, co2, regulator with solenoid and bubble counter, plus a feed pump and you're set. Though I'd DIY a second chamber, it'll allow you to utilize the co2 better and bring the pH of the effluent up a bit.
yeah, it was a basket case. His stuff might have gotten better but it's basically a pre-assembled DIY reactor.
You will need a $15 needle valve-check out reeftekdotcom under the assesories page of the "store"
The flanges on mine had no groove for the o-ring to be seated--you will need a large tube of spa lube from the local pool shop (silicone lube). Make sure it says "safe & non-toxic" on the tube before you use it. You will need to grease those flanges heavily to keep them from leaking.