I was extremely lucky getting the acrylic cylinder from a friend who was going to build his own protein skimmer, didn't, and allowed me to reap the benefits of it just sitting around at his place.
The tank is about 40" deep and the acrylic cylinder is 30" so the whole working end will be completely submerged-trapped air shouldn't be an issue.
How does the one you made work for you? What size drain hose is that? Thanks
Nice friend! The quote I got for a 4' piece of 6" acrylic tube was $150...a bit more than I wanted to spend.
I was able to get ahold of a small scrap piece of acrylic cylinder and I took it down to my local plumbing supply house. They had an ABS fitting that created a nice tight seal, but I gave up on the idea of using acrylic when I found out the fitting and the acrylic tube would be so expensive.
I would suggest taking the 6" acrylic cylinder to your local plumbing supply yard and ask them if you can poke around and see if they have anything that would create a more secure seal; test fit a bunch of fittings to see if there is anything that would work.
My siphon works really well (besides not being able to see what I'm sucking up

). I also have a ball valve on mine and I have to valve it back to prevent gravel from being sucked up. I put a mesh lingerie wash bag at the end of the hose to catch any gravel that I inadvertently suck up (see pic below). The tubing I use is just cheap 1.5" sump pump tubing. Surprisingly, it's held up really well over the 3 years I've been using it. I put my ball valve about 6' down from the tubing since I didn't want to lose my siphon when I moved the vac from one opening in my tank to another. You won't have that problem though, since it looks like that tank is wide open.
I was going to use pool hose like you did, but I went cheap-o on mine. Yours is basically what I set out to build, but I'm a cheapskate and I decided I didn't want to end up spending $300+ to build a gravel vac. Yours looks awesome!
Wash bag to capture anything that gets sucked up:
That filtration room is epic! I would hate to see the power bill though.
