Ya, to reiterate what everyone else is saying: Stop. Stop carbon dosing. Stop all/calc dosing.

Just do water changes.

I was helping someone recently who was having similar problems and instantly saw the problem. Pulled all dosing offline and within a week all the SPS were fine. A couple weeks out and they looked great. All tests showed the water beforehand looking fine but I'm 99% sure it was alk swings that were causing it.

Super low nutrients combined with alk swings from dosing is the perfect RTN recipe. If your tank is relatively new, you really shouldn't need to be dosing anything! There's no need to dose alk/calc if things aren't happy (because they ain't growing!) and nutrient levels should be controllable with only water changes and controlled feeding habits (for the first few months at least).

Why didn't you use any of your old rock? Is there algae all over it or pests? If not, I bet your tank would do a lot better with it in the system. As long as there are no pests and it is not cycling (no ammonia), then put it in the sump. If it won't fit in the sump, then put it in the tank even if you're just tucking it in somewhere temporarily. Between that, a few water changes, and stopping dosing I think you'll be back on track.

Ok I will stop carbon dosing immediately when I get Hom. I was told it was to help me raise my bacterial count faster. As I was dosing it from day 1 while tank was cycling. My old rock was removed because they were too big and filled with algae n not too pouris. I actually had way more death with algae than anything else in my old system as it smothered everything to death. Sps LPS and softies. I would like to thank everyone for ur help and input, I appreciate it very much. So for my game plan I'm gonna stop carbon dosing and Mybe slightly increase my rowaphos a bit over time. And of course STOP BUYING SPS lol. Well not gonna quit sps altogether but I will stop getting more for atleast 4-6months as my tank matures. I can't rly stop all dosing as my lvl does drop pretty fast as I do have a lot of corals now but I do notice my cal is always a steady 420 n doesn't change. Mybe I can reduce my cal dosing a bit over time to see if it changes or not

I see no reason to discontinue calcium and alkalinity dosing to maintain levels. Just make sure calcium and alkalinity aren't increasing while the corals are stressed. I would work on getting the magnesium up too. Just quit the carbon dosing.

Ok carbon dosing has been stopped. My Alk is somehow dropping so something must be growing. Cal stayed the same n mag is now increased to 1140. I don't see any sps getting worse. LPS is more puffy.

alk will reduce based on acids in the system. The tank produces various acids as part of being and alk is consumed while buffering pH. If Ca is staying constant, nothing is growing (worth worrying about)

Just going to jump onto Jason's thread here.

So if your calcium is going down but alk and mag are holding steady/very slow decline is that normal?

over what time span are you testing the calcium to see its drop? how much of a drop compared to alk?

Well my calcium isn't dropping holding steady at 450 but its being dosed a tiny bit, 12ml a day. I was dosing my alk the same but it was going up slowly every day. So I turned the alk off for now. I check my magnesium(1350) once a week after my water change. Add if needed. Have been checking calcium and alk every day since adding doser.

testing calcium drops daily is pretty much impossible to do on hobby test kits the margin of error is to high for such a low drop , test it weekly and find out what the weekly drop is , basically if your calcium is holding steady at only 12ml but alk is rising a bit then both need to be a lower dose , try 8mls and see what happens. eventually calcium will find a happy medium with alk.


tinkering for a bit with both is ok at first but if your using an equal measurement dosing product like 2 or 3 part then youll eventually need to set both the same.


as they say dose based on alk numkbers not calcium numbers. so test alk daily for a while and calcium once or twice a week and find what both needs are:)