Whew, just got through all ten pages. I should have + quoted as i went.
The LEDs are awesome. My LFS
has two over a 20 and they have maxi carpet nems in it. There is a spray coating they make to protect the solders from salt.
Before the sump broke, there was sand in the return pump area. Bad Idea. Now with the three separate buckets you will only get flow through the bulkheads, which is OK. But fuges need good flow too. make sure a return and a drain cross the fuge. If you want plankton growth put the 6500Ks down there on a time opposite the tank light time. Ph may not have been just from the rocks.
Why not a coast to coast drain rather than the vertical one? with the bulkheads at the top, anything below the bulkhead is a waste. Then you could have done the bean animal style and had a measure of safety.
With the utmost respect, I think what I see is in your "experiment" you are testing the limits of what can be done rather than what has been found to work in most cases. for example the drilling of the side glass for the closed loop. if you were dead set on closed loop there is a very easy way to hang the outlets into the water on motorized elbows that randomize the output to avoid dead spots on such a large tank. Wavemakers, and programmable power heads would have been a huge improvement. the sun, my window only gets late afternoon light, and you can see the spots where the algae grows magnificently. in my 75 it is easy to trim and remove. this will be impossible in your tank. But I like the green and wavy background. the silicate sand? only time will tell. The lack of skimmer and the overstocking, again time will tell.
One last thing, a fellow reefer that made his own 800 gallon acrylic tank (Freaking Awesome) with DIY led
's and such, also built a small room outside of his home for the sump and all the other equipment. if you were to put a shed outside, you would have a lot more room for the eventual calcium reactor, Kalk
stirrer, phosban reactor, skimmer, algae srubber, etc. Of course being in the great white north, insulation would be a friend.
I hope your lack of posting is only because nothing is changing. but like I said above the Ph may not only be from the rock, of which, you could remove and throw back into the ocean. and start with a little natural LR
which can go in the sump later.