Just sharing my journey in hopes there is something here that sparks an idea you haven’t tried yet. R2R has been my main source of reading and this is what I am trying based on my research.
I’m going through the same stuff you are but about 1month into trying to fix my problem naturally. Random Pale SPS Even lost a few long term SPS 5+yrs that where to far gone to save. In this newer tank. It’s about 1.5yrs old with set backs along the way. some SPS have been ok up until I got unbalanced with No3 and PO4 to zero and Alk to high. Cyno soon followed once I hit zero and random pale SPS.
So here’s what has helped with my SPS so far.
Cyno I’m still battling back and fourth.
1. No3 held no lower then 3ppm Po4 minimum .03ppm no higher then 1ppm. This can be + or minus as long as it stays consistent to each other from what I’ve learned. Alk also plays into this as well. Lower No3 lower Alk 6.5 to 7.5 ish anything over 8 and I had trouble with lower nitrates and Phosphates.
2. Flow! Up your flow to the point where it’s a washing machine in your tank but not blasting anything direct. SPS will start to extend the polyps over a few weeks. Random whirl wind burst is good from cross flow. This will help with cyno too. I don’t have many soft coral but do fine with burst too just not constant direct flow.
3. Using AB+ to feed starving pale sps until my NO3 and PO4 are balanced so the corals have a natural source. Also using
Brightwell Restor.
4.
Microbacter 7 added daily to out compete the cyno’s food, fingers crossed. This is a long journey. I read at least 3 months min. I know sounds counter productive with No3 and Po4 and Bacteria eating it up but this is suppose to help balance it where it’s not stripped out instantly but slowly and balanced naturally.
Bio load increases bacteria increase bio load decrease bacteria decrease slowly.
5. Started adding trace elements since I don't do many water changes. I use to have a 35g for yrs and never did water changes and the tank was insanely packed with colored SPS. Never once did I have a cyno outbreak but I did allow other algae to grow good or bad. Looking back I still don’t know how but I’m trying to apply the same method to the bigger tank now with out the bad algae.
6.Just started adding Phyto to help pods grow to eat micro foods left behind to out compete cyno and other bad algae.
6. I feed my fish decent and am trying to add more fish as quickly but slowly as possible.
So far my pale SPS are coming back my other SPS that where doing good already have gotten brighter and stronger.
Hope something here helps you.
I’ve been reading for two months straight trying to learn something new I might have missed/forgotten or need to do. I’ve been reefing for 15+ yrs. and always had luck with SPS from day one. So yeah cyno and balanced nutrients have been kick my … I guess it’s only a matter of time when something catches up too you and Reef Gods tell you to pay up. LOL
So I’m paying my dues and sharing what I have found so far. Good Luck!