High alkalinity levels in newly mixed saltwater

[Bxr126]

Happy Thanksgiving all. I have an issue mixing new saltwater and I am fresh out of ideas. Ill save you the long version. I am switching from IO Reef Crystals to Fritz RMP. Since the switch I have experienced 2 alk spikes directly following the water changes. Approximately 15%. On the third try I tested the water prior to adding it and tested at 13.7. Multiple tests with 3 different test kits. Mixed new batch from a different box. Similar results. Now I am on box 3 from a different lot number and I am experiencing the same results. Obviously I'm screwing something up. I never had an issue with the reef crystals. I'm following the directions to a T. Using clean container, heating water, RODI.... any ideas?

 

[Flippers4pups]

There are some of us had similar issues with high alkalinity with fritz blue box. I for one was one of them and followed by some coral die off. In my case it was several water changes down the road before I noticed my corals were palling. By then it was to late for some. I did test my newly made saltwater and found it was very high in dkh. 14.5. I then discontinued using it and switch back to my old salt. IO.

You can adjust the alkalinity using muriatic acid to bring down the alkalinity in newly made saltwater.

 

[Randy Holmes-Farley Verified Community Expert]

Smaller water changes are another way to minimize the spikes.

 

[fcmatt]

Are you sure the water is at 1.026 or whatever u want it to be? Are you calibrating your refractometer with ro/di or calibration fluid?

Also are you using blue or red box? It seems u did not make that clear