An ATO will be a game changer for you. The cost can be decent for a good quality one (80-120) but they scale up to any system you may have in the future. And, they'll help with salinity and overall stability.
One other thing. I haven't had luck with cyphastrea yet either. I talked to Marc Levenson of melevsreef (huge source of info for me when I was first learning) and he suggested that some tanks just need to wait until they're ready for certain corals. I plan on waiting until the 1 year mark to try them again. Not saying that's your issue, but perhaps you will have future success.
For what it's worth, it's still alive, so you're close to getting things figured out for it. Hope it turns around