jnarowe - I actually prefer the look of hard plumbing to flex PVC, which is why I went that route. I understand your point completely, that all of the 90's and 45's will impede flow, but I'm not really concerned. The pump is a Barracuda, which is way more flow than I'll need from my closed loop. I originally thought I'd have to dial it down anyway, so maybe now I'll just run it full bore. At any rate, I don't think those turns are going to be that big of a problem due to the size of the pump. There will also be flow via 2 separate return pumps, one from the sump and one from the chiller, in addition to a wavebox, so I think I'll be okay.
melev - Happy you're following along, your input is always valued and appreciated. I guess I could have glued in the bulkheads, but I'm not sure how that would affect the rubber gasket. Haywards have an awesome reputation for their leak resistance, and with the PVC bottom I was able to tighten them without worrying about cracking glass, so I really don't think they'll leak. Regarding your tank question, I guess you could contact AGE and ask about PVC on the sides. I liked your concept, very interesting. Actually, AGE don't deal with Joe Public, so you may need to ask them your question via a LFS. If you want Kingfish's number I'd be happy to give it to you.
cbui - I didn't think I'd need straps to support the plumbing, but that would be an easy addition. Do you feel it will be necessary? Hopefully I won't have to take the 4-way apart for cleaning too much. I intentionally installed it without the drum so that the initial sandstorm won't foul it, so I'll have to take it apart at least once to install the drum. Guess I'll see how difficult it is to do at that time.
clownnrd - Thanks for looking at the images so closely. I checked it, and the 7 o'clock SUBV is seated correctly. Glad to know you've got my back
. The tank is still dry, and the OM isn't on, but I'll check the heat situation once it's up and running - thanks for the heads up. The tank won't be barebottom, I plan on having a 1-2" sandbed. I don't like the look of barebottom tanks personally, except for naka's.
EBOLII - The only reason for gray PVC is that it looks cool. I simply prefer the aesthetics of the gray. Jonathan's right in that store-bought PVC is Schedule 80. Sched 80 PVC is thicker and tolerates higher pressure, but the downside is a slightly smaller diameter. I therefore went with gray Schedule 40 PVC that I purchased on-line, along with gray Schedule 40 fittings and spa flex.