Pond Boss Forums AERATION Systems questions making a homemade base for Vertex

Hi all, I am adding air to my pond. I have on the way two 9 inch Vertex difussers, just the difusser part. Two questions.
First I have read tons of great information on here. I am going to mount these two diffusers together and drop them in 17 to 18 feet of water at full pool. One thing I had read was to place them about 1 inch apart for maximum lift. I then read on the FAQ they should be 6 inches or so apart for deeper water. What is the consensus for spacing at these depths? I know the pre-made version from Vertex shows to be close together but they also list one for shallow water that their photo looks to be the same.
Next, should I just use PCV to connect these? I had thought about galvanized pipe and fittings but wasn't sure if that would be problematic I understand that can flake off and didn't know how it would work when completely submerged. It is just stronger than the plastic but didn't know that that would be an issue. Thanks
Dave

Disk membrane diffusers 1"-2" apart; use PVC Sch40 for the manifold.

Thanks Bill. I have my stuff ordered from esshup I will post pics as I get this together.
Thanks
Dave

If a person wants to do screw together fittings, schedule 80 PVC is more rigid and is available in various length joints like galvanized pipe would be.

It is quite a bit more expensive, but I have found it to be a good substitute to metal pipe where I wanted a screw together assembly but did not want metal that could rust.

At a nearby Lowes they keep in stock common L's, tee's etc plus a number of different length nipples. For example a person could take a Tee, two 6" screw nipples and a couple of L's to make a manifold that would screw rather than glue together.

Not saying it is better or even needed, just another option people might not think of or know is available. It works pretty much like screwing galvanized pipe together with fittings like unions and most of the equivalent metal fittings. Our local Home Depot does not carry it in stock but about any industrial plumbing supply should. And Like I said, Lowes in a nearby town keeps it in stock.

Thanks Snrub I was at Lowe's last night checking things out. I got my fittings for my manifold since I have my pump. I can assemble this and make the box for it. I'll have it done this weekend and expect to have my weighted hose and disks next week. Its all coming together nicely.
Thanks
Dave

Do the diffusers come with check valves? If not, I would get some.

Vertex - yes, built in check valves.