interestingly my more expensive Sps have been rock solid. I was struggling to maintain alk with kalk and switched to 2 part. Took a week to get it dialed in but finally stable at 7.7dkh. Clam lost organ 3 weeks ago, pretty much waiting for it to die but it seems to be hanging on. Bright side is alk is finally stable and 2 part lasts soo much longer than kalk.
Might add a few more acans. Also my trochus bred a huge amount so I have like 20 babies growing super fast.