[KPG007]

Back in November I bought Dave's (Acepumping) 200g tank (+ 100g sump). Over the course of the next few months I slowly moved everything in got all the equipment installed and finally got my doser dialed in.
Now after 8 years of reef keeping, I know how to keep them looking good, and know whats required to keep them healthy. My problem is, I'm a bit lazy with the small stuff. Water changes? once a month or two...or three. No problem as I dose like a machine. Carbon? do you change it after 3 months or 6? Whatever. Testing? YES, looking at my logs I last tested...2 months ago.
With the new tank and the doser now hooked up I was testing weekly until I got it dialed in. Then I forgot about it. Fill the canisters when their empty and let everything grow.
Tank was looking good, polyps were huge, Acans big, extended and growing. There were a few issues. Some SPS not holding color. A couple fading, bleaching or browning out. Now this is a new setup and there are always issues that come up. Too much light? not enough? flow? water quality? It all can cause these issues.
So one day I did a water change. Next day, acans are closed up tight and polyp extension on the SPS is about half. This had me scratching my head. How does BETTER water make a GOOD tank go sideways? Things get marginally better over the next couple weeks. The acans though are still PO'ed, so I transfer them to another tank. They slowly return to normal.
With the SPS not really perking up too much, last Thursday I decide to do another 10% water change. When I walk into the fish room on friday the tank looks like a bomb went off. Bright green slimers are now brown, actually ALL SPS are now brown with zero polyp extension. Prized corals are fading. Strange though, Zoas and most LPS look PO'ed, but OK. I quickly transfer as much SPS out of the tank as I can.
Spent saturday freaking out, trying to figure out what happened. Everything is working like a charm. Eventually I decided I had a look at my saltwater changes (but I'm adding good water to a good tank! Salt is from buckets 2/3rds used! All other tanks are fine! It can't be the new SW, can it? Turns out I had another bucket of SW mixing. Test were coming out fine. Ca was a little low and Alk was a little high at 9.9. So that wasn't it. Had the test kits out and thought I should test the tank. Tested Alk first - whatthe heck? its coming in at 3 Dkh! Test again. 3 again. I checked the doser and it initially looked good. Then touched the hoses and it basically came apart.
What seems to have happened is, the hose connector (joining the hose from the canister to the hose for the doser) cracked. It started drawing air instead of liquid, but still enough liquid that I saw the canister emptying, but much slower then usual. Over the course of a couple weeks the Alk level would go down to around 3 then I would hit it with a 10% water change with 9.9 Alk. Things would go into shock. The first time maybe the Alk was a little higher in the tank and the shock not as much, but the second time was huge.
I have now bumped the Alk up to the 6-7 range, but the damage is done. my Red Dragon colony melted away, a few others may go too. All my SPS from that tank is brown. On the bright side is Zoas look fine, LPS is 60-40 to the good and I think a lot of the SPS will recover (eventually).

Has anyone else done something similar? What do you think recovery time will be? Do you think they will recover at all?