Tank Upgrading!

[Lemons]

howdy, folks! I'm thinking of upgrading my reef because I'm apparently never happy with what I have lol.

My current tank is a 90 gal 4' x2 'x18" with a 30-gallon sump. I was browsing on my local classified and saw a whole bunch of great deals for tanks that are 200Gal+ for under 1000$ 6'x2'x2.5'

(i have no idea if that's a good deal or not... all I know is most aquarium stores start quoting those around 4000$)

So ideally what I'd like to do is "acquire" this new behemoth. Then find a way to basically do a "fresh" start...

For the past little while, I've been fighting on/off flashing and scraping of like 2-3 members of my tank. I've dosed prazipro once and did not really see any improvements (although it was only two doses, I could have done more rounds of treatment) and I'd love to just have happy healthy fish and not have to worry if maybe they're slowly being destroyed by parasites/ going insane because they're in a glass box instead of the ocean.

now that's the fish side of the issue.

now the rock/coral side is I'm currently experiencing bubble algae. so I'd love to not have that turn into an even bigger issue when it involves me moving my corals.

So would anyone have any idea/ experience how to maybe accomplish this fresh start without any transmission of possible fish disease/ nuisance algae?

 

[Lemons]

I was considering just getting all new dry rock/sand for the new tank, letting it cycle for a little bit then transfer my corals, and basically letting it go fallow. while I use my previous tank set up as a QT for all my fish in it.