Join Date: Nov 2004
Location: PA/MD/DE tristate area
Reactor - mine works great
Thought I'd pipe in (ha, no pun intended, but there it is!). I built a reactor from PVC pipe and fittings and it has the water flow from TOP to BOTTOM, with the CO2 injection at the BOTTOM. It is filled with an unrolled plastic kitchen scrubby (I got 12 for $1 at the dollar store, so for that price, I just will throw away the stuffing when it gets clogged, if it does.)
What happens is that the bubbles get injected in the BOTTOM of the reactor and try to float up through the scrubby mesh matrix. The mesh matrix holds them back if they are too large a bubble, and the water flow is constantly pushing the bubble DOWN while the bubble is trying to RISE, so the bubble is basically suspended at the same position until it dissolves. I have no trouble getting the bubbles dissolved completely and my reactor is running a 75 gallon, KH 8 tank at 25 ppm CO2.
When I first set it up and was getting the bubble stream timed correctly, I put too much stream through at first and the bubbles accumulated at the TOP of the reactor, making an air pocket. This sounded like a trickling fountain in the house. All I had to do was bleed off this air pocket, and then I could crank up the bubble rate fine, no noise.
My reactor is plumbed in line onto the output line of and Eheim 2217.
IMPORTANT NOTE: I suggest you plumb your reactor with quick disconnects on either end WITH spigots. I spent an extra $15 for the spigots/disconnects (I had to buy the eheim ones to match up to the disconnects that were already on the eheim output line), but if there is ever a need to get to the reactor (such as to bleed off a bubble or to clean it out), all you do is turn off the spigots, disconnect, and re-connect your filter line to itself, without the reactor. Then you can fool with the reactor easily and not worry about no filtration on your tank. Also, use screw ends on the ends of the reactor rather than glued caps. Then, you can get inside the thing very easily to clean it out.
My reactor is 3 inch PVC and is about 18 inches long.
Hope this helps. I was suprised how simple it was, if done this way.