Your tank looks great. Did you do anything different this summer?
As most reefers know keeping a sps dominant system is the most challenging where stability is the key to success. You have to love the challenge and partially nuts as well. After being in the saltwater hobby since 1990 and keeping reefs since 1997ish I've gone through alot of different systems/ways of reefing, alot of ups and downs, and unfortunately alot of losses. Summer as most experienced reefers know, brings alot of challenges not with just the increased water temperature, but with bacterial and dino blooms. In fact most wholesalers and importers, I've talked to don't import alot of livestock during our summer months because of these challenges.
What I've attributed to my reef doing better this summer is really understanding water chemistry. I've been using Andre's Reef Moonshiner method since January 2020 and it's really worked the best for me. Also Greg C. convinced me to suck it up and invest in the Alkatronic and so last October I bought it for my birthday and boy has that machine been a game changer. I religiously test Alk once a week, along with Ca, Mg, NO3, PO4. But I didn't realize how much Alk was fluctuating in my system. So by monitoring and keeping Alk very stable the sps have been very happy. And lastly, upgrading my chiller to a 1/3 hp has allowed me to keep the tank at a constant temp of 77-78 F. Again stability.