Folks, if you've recently upgraded or renewed your annual club membership but it's still not active, please reach out to the BOD or a moderator. The PayPal system has a slight bug which it doesn't allow it to activate the account on it's own.
And you created the next generation of reefer. Our town a few years ago switched something in our water and killed off all of our monti's, I actually corroborated this with another local reefer. Nothing else was harmed, just all of our montis died. They are coming back now as a few polyps...
Yeah, you can also use flatworm exit, but be careful they can release toxins when they die and if you have a lot of them (and it looks like you do) just use carbon.
We added some stunner strips to the tank because we were missing the color and shimmer of leds. So now we get some windex pictures, but at least they look cool.
https://www.clearviewlids.com/collections/elos-clearview-lids
This is whom we used for a lid and highly recommend, doesn't look like they have your tank as a stock one, but I would reach out an ask.
We use a flipper scraper but every week or so we just clean it manually
Looks like you have a great setup to start and taking it slow is always the way. For water changes, you can go through the floor or just get a really long piece of tubing to run the water changes from the basement up stairs.