Consecutively High Calcium

[coralboi56]

So I test my water 2x a week and finally have acceptable parameters
Alk: 8.62
Phos: .05
Mag: 1120
Nitrite: .02
Nitrate: 5

The only test not in an acceptable parameter is calcium. It's been reading consistently in the 520-530 range since the beginning of the month, and has been reading on the higher side (above 480) since January.

Is it just a bad checker? Or is there a reason why it's staying high. I tested my water right after a water change and alkalinity went from 11.08 to 8.62 and Magnesium went from 1230 to 1120 so the corals are definitely using those. I've been using the Hannah calcium tester and following the steps EXACTLY to a T. Any advice is appreciated!

 

[ryanjohn1]

How old is the calc reagent

 

[Randy Holmes-Farley]

400-550 ppm calcium is fine.

The magnesium change is test error. Magnesium never depletes more than 1/10th of the rate of calcium depletion, and neither depletes if alkalinity is not depleting significantly.

 

[coralboi56]

400-550 ppm calcium is fine.

The magnesium change is test error. Magnesium never depletes more than 1/10th of the rate of calcium depletion, and neither depletes if alkalinity is not depleting significantly.

Yeah I don't always trust my mag tests lol. The reagent and the saltwater are suppposed to add up to 9mL, but sometimes for some reason I end up with 8mL. The most recent test (the 1120 reading) I for sure trust. Just because it looked like the actual 9mL solution.

 

[coralboi56]

How old is the calc reagent

I ordered the most recent reagents on 10/28/22 and they don't expire until next year

 

[Uncle99]

I ordered the most recent reagents on 10/28/22 and they don't expire until next year

I had same results with this checker.
Varied results, always on the higher side.
Went back to Salifert for CA…..it’s shows 450ppm which I expected.

 

[Randy Holmes-Farley]

Yeah I don't always trust my mag tests lol. The reagent and the saltwater are suppposed to add up to 9mL, but sometimes for some reason I end up with 8mL. The most recent test (the 1120 reading) I for sure trust. Just because it looked like the actual 9mL solution.

I would suggest this method instead of trying to measure magnesium and constantly make corrections that are from test issues:

Just say NO to magnesium testing: RMM is born

OK, this thread has been many years in the making, and I'm posting it here since folks in the chem forum are probably already tired of all the threads relating to problematic magnesium testing. I'm going to propose a method, let's call it the Randy Magnesium Method, or RMM for short. All good...

www.reef2reef.com