Okay, deep clean completed.
Here are a bunch of pictures detailing my process... I found a 1.5" rubber stopper that I wedged in the center pipe, and it held just fine the entire time. I followed the video and gently poked the sand w/ the hose running a light stream of water. A couple of times when I started pulling the hose back out, it got kinda "stuck" - I think under the laterals or the outlet center pipe (it's horizontal since I have a side-mounted valve). So I very, very carefully pushed and pulled a bit, reaching further down into the sand w/ my hand, and wiggled the hose side-to-side a bit while pulling, to "free" up the hose. It seemed to work, but spooked me a bit because I know the laterals are like the holy grail of the filter. So all the small leaves and bugs and stuff started floating out the top...
The water was always this kind of "greenish grey" color - the guy in the video said to do it until the water was clear... not sure if that meant clear as in "no more leaves and bugs and stuff coming outta the top" or "clear like tap water". I'm thinking the former, so after maybe 10-15 mins later, no more stuff was surfacing to the top:
Then I scooped out some of the water with a cup so I could get my rubber stopper out...
Then after I got it back together I emptied the pump basket, backwashed for about 5-6 minutes then rinsed for 1-2 minutes. Here's the sight glass after 3 mins:
And after 5 minutes:
There was still a tiny bit of what appeared to be sand(?) or dust or something. When backwashing, are you supposed to wait until the sight glass is _totally and completely clear_? I was worried my water level would have gotten too low if I kept waiting, so I switched it to "RINSE" for 1-2 minutes and flipped it back to "FILTER".
Then I checked the FC and it was down to 18.5 (after running around looking for sand all afternoon)! So I added a 128oz jug and 3 cups of 10% liquid chlorine to bring it back up to 24 and got to brushing. Here were the steps before brushing the whole pool:
"Still battling organics" indeed!! THEN after I brushed the whole thing I checked the steps again, and look at this...
This algae stuff is relentless. So now it's time for dinner and that wasn't exactly how I wanted to spend my afternoon, but hopefully this will help the filter do its thing. Should I check the FC in another couple of hours to make sure it's at 24?
Now I'm wondering if I should have done the salt water overnight thing instead of the 'deep clean', hmm. If this is how needy this Zeosand stuff is going to be, I'd rather just use "real" sand I think. Ugh. Anyway hopefully tomorrow things will be at least a little tiny bit clearer. We'll see.
Thanks again!