Another update. I've moved on from tile-worker to plumber:
The thing in the back left-hand corner is the CO2 reactor. It's made of 3" PVC pipe. You can see the CO2 tubing entering about 2/3 of the way up. The valve above it is an air bleed-off valve for use when priming the system. To the right of the reactor is the Eheim 1260 pump. The pump outlet is the 3/4" vertical line, where the water can be routed through the wall to a floor drain or up to the reactor. Once the water leaves the bottom of the reactor it goes to a manifold where it can either be routed to the UV unit or bypass it for a direct return to the tank. The inlet to the main pump is the 1" horizontal PVC line. Two valves there select either water from the inlet strainer in the tank or from the 105 gallon storage reservoir behind the wall.
Per Gnaster's recommendation, I've used unions in strategic places to make removing and servicing components easy. This was VERY good advice, since ease of maintainence is the name of the game.
A 50% water change takes about 20 minutes from start to finish and only involves cranking a few valves. This is absolutely my favorite part. In many aspects, this tank will be easier to maintain than my current 46g bow.
In this photo you can see the 3/4" PVC return line, which enters the tank at the mid-point, along the back wall. It then flows down to an inverted "T" which lies at the level of the substrate. The horizontal limbs have small holes drilled every 2" along the top to function as a large spraybar. Even with all the plumbing, intake strainer, reactor, and UV unit, the circulation in the tank appears to be even and fairly strong. As near as I can tell, the system moves about 350 gph actual. One of the main goals was to evenly distribute the CO2 in the tank. Hopefully this will do the trick.
I currently have one of the Eheim 2217's hooked up with its Hydor 300W in-line heater. So far I'm quite impressed with the Hydor unit. The single heater raised the tank from 60F to 76F in about 10 hours. I'm waiting on some additional 5/8" tubing to connect the second Eheim & Hydor. The return lines from the two canister filters will be placed at the center of the tank with one directed toward each front corner. My goal here is to provide enough surface movement to avoid a surface film, but not so much that the CO2 is wasted.
The Manzanita wood has been soaking for about 4 days. A few of the smaller pieces are already sinking, but the big ones will take a few more days. Despite what anyone says, Manzanita wood does contain some tannins. After 24 hours the water was quite darkly tea-colored. The leeching does seem to be slowing down though.
The lights are supposed to arrive this week, so I'll be transitioning from plumber to electrician. I'm planning on keeping the electrical stuff to the right side of the cabinet. The ballasts will be up off from the floor to hopefully protect them from stray water.
Still to do: install the CO2 regulator & pH controller, wire the lights, find some rocks for hardscape, arrange the driftwood, select & order plants, and ...... finally, plant the stupid thing. Maybe sometime within the next week or two.
