The original and 2nd version 24" sieves are still working great. The first unit installed in Sep '23 and the 2nd spring '24. They've been running continuously since installation. This includes going through two winters.
The clear tops have not had any issues and have not bowed much more than maybe 1/16" more in the middle from when they were first installed. I couldn't be happier with them.
That being said, they are housed in a green house down in a pit so there's no real direct sunlight on the tops. I think if I were to make these for outside use I'd use a thicker piece of acrylic for the top.
I finally got around to installing the 18" unit about 3-4 weeks ago.
It's been working great and I'm pleased with what it's doing.
I would like to share a couple observations though.
First, on my 2" drain line I have a very minor leak. Most likely because I lifted the unit into place with the drain and feed pipes. It hasn't affected the operation and I'm sure just a bit of caulk on the outside will solve the problem. I'll try to post a video.
Second, I didn't need to make the sieve as long as I did. The top 4" or so really doesn't do anything. It's not an issue because the water hits the sieve starting at about 5" down but I could have saved money not buying as long of a sieve.
Overall I'm extremely pleased with my sieves and I hope this thread can help someone else out.