Stopped dosing ca for 5 days and my ca isn't dropping.

[richiero]

Hi, I stopped dozing calcium five days ago because all my test kits and mastertronic were testing hi like 560 , 561 and some Hanna test 600... I been doing the balling method with AF for 7 yrs and never had this issue.

Now for the last 5 days I have dosed no ca or mg only alk to maintain my Dkh between 9.3 and 9.5 with my Alkatronic. All does numbers are on point with my cross reff test. But my ca hasn't moved a bit. My reef is moderately to a little over moderately stocked with sps , lps , and mushrooms. Why wouldn't my ca be dropping I never have this issue ?

All test kit and reagents are brand new.

Ca 561
Mg 1500
Alk 9,18 - 9.35
Salt 1.026
Thx for any help

 

[winxp_man]

That Hanna checker is about 100 ppm off. Here is why. You need to use distilled water with the processes instead of rodi.

Also some will come say Salifert. I have found both to be similar with little ppm difference. What I did find with Salifert is that after about two three weeks of opening the kit, the kit ends up being off. I have tested this three four times now. I have calibration solutions from four different brands. And the Hanna calcium was still closer to calibration solution compared to Salifert. The Salifert I can trust for about a two weeks tops.

Don’t ask me what’s going on cause I don’t know aside from the issue being that once open the Salifert reagent just goes bad. I have seen this now for the past month as an issue with the Hanna Alk and Salifert Alk kit. After about two weeks they all read off by about 1dkh. Careful chasing numbers, and get several brands of calibration solutions to test against before dosing, not just one brand.

Almost killed my $9-10k coral tank thinking the checkers were good to go. It’s the reagents that are bad. The Hanna for example reader is dead on with new reagent.

Just something to think about.

 

[mcarroll]

Interesting.

I've never had cause to suspect Salifert Ca kits – no surprise results even after calculated Ca doses and post-dose checks with the test kit.

Results for me have always been as predicted (ie adding XX ppm of calcium yeilds an XX ppm increase on the test kit). I've been using Salifert test kits since the mid-2000's, so I've done this many times over the years....tho I admit not lately since I don't need to test much these days.

I do always take care to have reagents open only long enough to get the quantity needed out, but hopefully that's standard practice for everyone sine freshness matters. (IE there's an expiration date on the package for a reason)

Easy enough for anyone to test their kit if they are wondering about this:
1) make fresh saltwater
2) test calcium
3) dose XX ppm of calcium
4) re-test calcium
5) find an XX ppm increase in the tank's calcium level

If the re-test doesn't match the predicted result from the dose then your kit might be expired....and I don't trust *any* test kits past their expiration date.

I would ask for a refund or exchange if you get bad results before the exp date. That's a defect.

 

[winxp_man]

Interesting.

I've never had cause to suspect Salifert Ca kits – no surprise results even after calculated Ca doses and post-dose checks with the test kit.

Results for me have always been as predicted (ie adding XX ppm of calcium yeilds an XX ppm increase on the test kit). I've been using Salifert test kits since the mid-2000's, so I've done this many times over the years....tho I admit not lately since I don't need to test much these days.

I do always take care to have reagents open only long enough to get the quantity needed out, but hopefully that's standard practice for everyone sine freshness matters. (IE there's an expiration date on the package for a reason)

Easy enough for anyone to test their kit if they are wondering about this:
1) make fresh saltwater
2) test calcium
3) dose XX ppm of calcium
4) re-test calcium
5) find an XX ppm increase in the tank's calcium level

If the re-test doesn't match the predicted result from the dose then your kit might be expired....and I don't trust *any* test kits past their expiration date.

I would ask for a refund or exchange if you get bad results before the exp date. That's a defect.

Yes strange for sure. I wish I could say it was something I was doing. But I pretty much have lab equipment haha. I use precision pipets to make things worse as to have less error to even the amount of water I add to a test vial. The magnesium tester is unstable it’s off by 100pmm +- some change.

 

[Garf]

Hi, I stopped dozing calcium five days ago because all my test kits and mastertronic were testing hi like 560 , 561 and some Hanna test 600... I been doing the balling method with AF for 7 yrs and never had this issue.

Now for the last 5 days I have dosed no ca or mg only alk to maintain my Dkh between 9.3 and 9.5 with my Alkatronic. All does numbers are on point with my cross reff test. But my ca hasn't moved a bit. My reef is moderately to a little over moderately stocked with sps , lps , and mushrooms. Why wouldn't my ca be dropping I never have this issue ?

All test kit and reagents are brand new.

Ca 561
Mg 1500
Alk 9,18 - 9.35
Salt 1.026
Thx for any help

How much DKH are you consuming each day? Calcium will only decrease about 20ppm for each 2.8dkh consumed, multiplied by 5 days, obviously. When did you start using the new test kit? This can also cause a wobble in reliability of data, along with the inherent wobbles of testing reproducibility.

 

[Randy Holmes-Farley Verified Community Expert]

To garfs point, calcium declines very slowly and is not easily seen in a few days unless the alk demand is very high.

560 ppm calcium is also fine. There’s no emergency to lower it.

 

[richiero]

How much DKH are you consuming each day? Calcium will only decrease about 20ppm for each 2.8dkh consumed, multiplied by 5 days, obviously. When did you start using the new test kit? This can also cause a wobble in reliability of data, along with the inherent wobbles of testing reproducibility.

Here is my alk over the last few days without dosing calcium


2026-09-25 02:00:00 9.26 7.78 28.18 8.27 Yes 4
2026-09-25 04:00:00 9.26 7.78 28.18 8.27 Yes 4
2026-09-25 06:00:00 9.29 7.78 22.14 8.30 Yes 4
2026-09-25 08:00:00 9.29 7.78 22.14 8.30 Yes 4
2026-09-25 10:00:00 9.35 7.78 0.00 8.35 Yes 1
2026-09-25 12:00:00 9.29 7.80 22.14 8.30 Yes 4
2026-09-25 14:00:00 9.26 7.82 28.18 8.27 Yes 4
2026-09-25 16:00:00 9.24 7.81 32.20 8.25 Yes 4
2026-09-25 18:00:00 9.38 7.80 0.00 8.37 Yes 1
2026-09-25 20:10:00 9.24 7.77 32.20 16.42 Yes 2
2026-09-25 22:00:00 9.21 7.77 38.24 8.22 Yes 4
2026-09-26 00:00:00 9.21 7.74 38.24 8.22 Yes 4
2026-09-26 02:00:00 9.26 7.73 28.18 8.27 Yes 4
2026-09-26 04:00:00 9.24 7.73 32.20 8.25 Yes 4
2026-09-26 06:00:00 9.29 7.73 22.14 8.30 Yes 4
2026-09-26 08:00:00 9.29 7.72 22.14 8.30 Yes 4
2026-09-26 10:00:00 9.35 7.73 0.00 8.35 Yes 1
2026-09-26 12:00:00 9.35 7.74 0.00 8.35 Yes 1
2026-09-26 14:00:00 9.26 7.75 28.18 8.27 Yes 4
2026-09-26 16:00:00 9.24 7.76 32.20 8.25 Yes 4
2026-09-26 18:00:00 9.29 7.78 22.14 8.30 Yes 4
2026-09-26 20:00:00 9.26 7.79 28.18 8.27 Yes 4
2026-09-26 22:00:00 9.24 7.78 32.20 8.25 Yes 4
2026-09-27 00:00:00 9.21 7.76 38.24 8.22 Yes 4
2026-09-27 02:00:00 9.26 7.75 28.18 8.27 Yes 4
2026-09-27 04:00:00 9.29 7.75 22.14 8.30 Yes 4
2026-09-27 06:00:00 9.32 7.75 0.00 8.32 Yes 1
2026-09-27 08:00:00 9.29 7.75 22.14 8.30 Yes 4
2026-09-27 10:00:00 9.32 7.76 0.00 8.32 Yes 1
2026-09-27 12:00:00 9.29 7.76 22.14 8.30 Yes 4
2026-09-27 14:00:00 9.14 7.78 25.16 8.17 Yes 4
2026-09-27 16:00:00 9.18 7.78 44.28 8.20 Yes 4
2026-09-27 18:00:00 9.24 7.78 32.20 8.25 Yes 4
2026-09-27 20:00:00 9.21 7.79 38.24 8.22 Yes 4
2026-09-27 22:00:00 9.18 7.78 44.28 8.20 Yes 4
2026-09-28 00:00:00 9.26 7.76 28.18 8.27 Yes 4
2026-09-28 02:00:00 9.29 7.74 22.14 8.30 Yes 4
2026-09-28 04:00:00 9.35 7.72 0.00 8.35 Yes 1
2026-09-28 06:00:00 9.26 7.72 28.18 8.27 Yes 4
2026-09-28 08:00:00 9.29 7.71 22.14 8.30 Yes 4
2026-09-28 10:00:00 9.39 7.73 0.00 8.39 Yes 1
2026-09-28 12:00:00 9.38 7.75 0.00 8.37 Yes 1
2026-09-28 14:00:00 9.35 7.77 0.00 8.35 Yes 1
2026-09-28 16:00:00 9.29 7.78 22.14 8.30 Yes 4
2026-09-28 18:00:00 9.29 7.79 22.14 8.30 Yes 4
2026-09-28 20:00:00 9.26 7.81 28.18 8.27 Yes 4
2026-09-28 22:15:00 9.38 7.92 0.00 8.37 No 5
2026-09-28 23:00:00 9.38 7.93 0.00 8.37 Yes 1
2026-09-29 01:00:00 9.29 7.92 22.14 8.30 Yes 4
2026-09-29 03:00:00 9.35 7.91 0.00 8.35 Yes 1
2026-09-29 05:00:00 9.26 7.90 28.18 8.27 Yes 4
2026-09-29 07:00:00 9.35 7.88 0.00 8.35 Yes 1
2026-09-29 09:00:00 9.32 7.87 0.00 8.32 Yes 1
2026-09-29 11:00:00 9.29 7.89 22.14 8.30 Yes 4
2026-09-29 13:00:00 9.29 7.91 22.14 8.30 Yes 4
2026-09-29 15:00:00 9.39 7.93 0.00 8.39 Yes 1
2026-09-29 17:00:00 9.35 7.95 0.00 8.35 Yes 1
2026-09-29 19:00:00 9.32 7.95 0.00 8.32 Yes 1
2026-09-29 21:00:00 9.21 7.96 38.24

Here are my last 5 days

 

[richiero]

How much DKH are you consuming each day? Calcium will only decrease about 20ppm for each 2.8dkh consumed, multiplied by 5 days, obviously. When did you start using the new test kit? This can also cause a wobble in reliability of data, along with the inherent wobbles of testing reproducibility.

My AT keep it in range and then calls for an all dose when it out if range

Here is my alk over the last few days without dosing calcium


2026-09-25 02:00:00 9.26 7.78 28.18 8.27 Yes 4
2026-09-25 04:00:00 9.26 7.78 28.18 8.27 Yes 4
2026-09-25 06:00:00 9.29 7.78 22.14 8.30 Yes 4
2026-09-25 08:00:00 9.29 7.78 22.14 8.30 Yes 4
2026-09-25 10:00:00 9.35 7.78 0.00 8.35 Yes 1
2026-09-25 12:00:00 9.29 7.80 22.14 8.30 Yes 4
2026-09-25 14:00:00 9.26 7.82 28.18 8.27 Yes 4
2026-09-25 16:00:00 9.24 7.81 32.20 8.25 Yes 4
2026-09-25 18:00:00 9.38 7.80 0.00 8.37 Yes 1
2026-09-25 20:10:00 9.24 7.77 32.20 16.42 Yes 2
2026-09-25 22:00:00 9.21 7.77 38.24 8.22 Yes 4
2026-09-26 00:00:00 9.21 7.74 38.24 8.22 Yes 4
2026-09-26 02:00:00 9.26 7.73 28.18 8.27 Yes 4
2026-09-26 04:00:00 9.24 7.73 32.20 8.25 Yes 4
2026-09-26 06:00:00 9.29 7.73 22.14 8.30 Yes 4
2026-09-26 08:00:00 9.29 7.72 22.14 8.30 Yes 4
2026-09-26 10:00:00 9.35 7.73 0.00 8.35 Yes 1
2026-09-26 12:00:00 9.35 7.74 0.00 8.35 Yes 1
2026-09-26 14:00:00 9.26 7.75 28.18 8.27 Yes 4
2026-09-26 16:00:00 9.24 7.76 32.20 8.25 Yes 4
2026-09-26 18:00:00 9.29 7.78 22.14 8.30 Yes 4
2026-09-26 20:00:00 9.26 7.79 28.18 8.27 Yes 4
2026-09-26 22:00:00 9.24 7.78 32.20 8.25 Yes 4
2026-09-27 00:00:00 9.21 7.76 38.24 8.22 Yes 4
2026-09-27 02:00:00 9.26 7.75 28.18 8.27 Yes 4
2026-09-27 04:00:00 9.29 7.75 22.14 8.30 Yes 4
2026-09-27 06:00:00 9.32 7.75 0.00 8.32 Yes 1
2026-09-27 08:00:00 9.29 7.75 22.14 8.30 Yes 4
2026-09-27 10:00:00 9.32 7.76 0.00 8.32 Yes 1
2026-09-27 12:00:00 9.29 7.76 22.14 8.30 Yes 4
2026-09-27 14:00:00 9.14 7.78 25.16 8.17 Yes 4
2026-09-27 16:00:00 9.18 7.78 44.28 8.20 Yes 4
2026-09-27 18:00:00 9.24 7.78 32.20 8.25 Yes 4
2026-09-27 20:00:00 9.21 7.79 38.24 8.22 Yes 4
2026-09-27 22:00:00 9.18 7.78 44.28 8.20 Yes 4
2026-09-28 00:00:00 9.26 7.76 28.18 8.27 Yes 4
2026-09-28 02:00:00 9.29 7.74 22.14 8.30 Yes 4
2026-09-28 04:00:00 9.35 7.72 0.00 8.35 Yes 1
2026-09-28 06:00:00 9.26 7.72 28.18 8.27 Yes 4
2026-09-28 08:00:00 9.29 7.71 22.14 8.30 Yes 4
2026-09-28 10:00:00 9.39 7.73 0.00 8.39 Yes 1
2026-09-28 12:00:00 9.38 7.75 0.00 8.37 Yes 1
2026-09-28 14:00:00 9.35 7.77 0.00 8.35 Yes 1
2026-09-28 16:00:00 9.29 7.78 22.14 8.30 Yes 4
2026-09-28 18:00:00 9.29 7.79 22.14 8.30 Yes 4
2026-09-28 20:00:00 9.26 7.81 28.18 8.27 Yes 4
2026-09-28 22:15:00 9.38 7.92 0.00 8.37 No 5
2026-09-28 23:00:00 9.38 7.93 0.00 8.37 Yes 1
2026-09-29 01:00:00 9.29 7.92 22.14 8.30 Yes 4
2026-09-29 03:00:00 9.35 7.91 0.00 8.35 Yes 1
2026-09-29 05:00:00 9.26 7.90 28.18 8.27 Yes 4
2026-09-29 07:00:00 9.35 7.88 0.00 8.35 Yes 1
2026-09-29 09:00:00 9.32 7.87 0.00 8.32 Yes 1
2026-09-29 11:00:00 9.29 7.89 22.14 8.30 Yes 4
2026-09-29 13:00:00 9.29 7.91 22.14 8.30 Yes 4
2026-09-29 15:00:00 9.39 7.93 0.00 8.39 Yes 1
2026-09-29 17:00:00 9.35 7.95 0.00 8.35 Yes 1
2026-09-29 19:00:00 9.32 7.95 0.00 8.32 Yes 1
2026-09-29 21:00:00 9.21 7.96 38.24

Here are my last 5 days

This was with my doser turned off disregard the dosing numbers nothing with dosed and this is how much my alk fell in that time.

2026-09-21 04:00:00	9.38	7.69	0.00	8.37	Yes	1
2026-09-21 06:00:00	9.29	7.70	22.14	8.30	Yes	4
2026-09-21 08:00:00	9.24	7.71	32.20	8.25	Yes	4
2026-09-21 10:00:00	9.04	7.72	36.23	8.07	Yes	4
2026-09-21 12:00:00	8.93	7.75	47.30	7.97	Yes	4
2026-09-21 14:00:00	8.82	7.77	58.37	7.87	Yes	4
2026-09-21 16:21:00	9.04	7.74	36.23	23.59	Yes	2
2026-09-21 18:00:00	9.09	7.78	31.20	8.12	Yes	4
2026-09-21 20:00:00	9.12	7.80	28.18

 

[Garf]

Here is my alk over the last few days without dosing calcium


2026-09-25 02:00:00 9.26 7.78 28.18 8.27 Yes 4
2026-09-25 04:00:00 9.26 7.78 28.18 8.27 Yes 4
2026-09-25 06:00:00 9.29 7.78 22.14 8.30 Yes 4
2026-09-25 08:00:00 9.29 7.78 22.14 8.30 Yes 4
2026-09-25 10:00:00 9.35 7.78 0.00 8.35 Yes 1
2026-09-25 12:00:00 9.29 7.80 22.14 8.30 Yes 4
2026-09-25 14:00:00 9.26 7.82 28.18 8.27 Yes 4
2026-09-25 16:00:00 9.24 7.81 32.20 8.25 Yes 4
2026-09-25 18:00:00 9.38 7.80 0.00 8.37 Yes 1
2026-09-25 20:10:00 9.24 7.77 32.20 16.42 Yes 2
2026-09-25 22:00:00 9.21 7.77 38.24 8.22 Yes 4
2026-09-26 00:00:00 9.21 7.74 38.24 8.22 Yes 4
2026-09-26 02:00:00 9.26 7.73 28.18 8.27 Yes 4
2026-09-26 04:00:00 9.24 7.73 32.20 8.25 Yes 4
2026-09-26 06:00:00 9.29 7.73 22.14 8.30 Yes 4
2026-09-26 08:00:00 9.29 7.72 22.14 8.30 Yes 4
2026-09-26 10:00:00 9.35 7.73 0.00 8.35 Yes 1
2026-09-26 12:00:00 9.35 7.74 0.00 8.35 Yes 1
2026-09-26 14:00:00 9.26 7.75 28.18 8.27 Yes 4
2026-09-26 16:00:00 9.24 7.76 32.20 8.25 Yes 4
2026-09-26 18:00:00 9.29 7.78 22.14 8.30 Yes 4
2026-09-26 20:00:00 9.26 7.79 28.18 8.27 Yes 4
2026-09-26 22:00:00 9.24 7.78 32.20 8.25 Yes 4
2026-09-27 00:00:00 9.21 7.76 38.24 8.22 Yes 4
2026-09-27 02:00:00 9.26 7.75 28.18 8.27 Yes 4
2026-09-27 04:00:00 9.29 7.75 22.14 8.30 Yes 4
2026-09-27 06:00:00 9.32 7.75 0.00 8.32 Yes 1
2026-09-27 08:00:00 9.29 7.75 22.14 8.30 Yes 4
2026-09-27 10:00:00 9.32 7.76 0.00 8.32 Yes 1
2026-09-27 12:00:00 9.29 7.76 22.14 8.30 Yes 4
2026-09-27 14:00:00 9.14 7.78 25.16 8.17 Yes 4
2026-09-27 16:00:00 9.18 7.78 44.28 8.20 Yes 4
2026-09-27 18:00:00 9.24 7.78 32.20 8.25 Yes 4
2026-09-27 20:00:00 9.21 7.79 38.24 8.22 Yes 4
2026-09-27 22:00:00 9.18 7.78 44.28 8.20 Yes 4
2026-09-28 00:00:00 9.26 7.76 28.18 8.27 Yes 4
2026-09-28 02:00:00 9.29 7.74 22.14 8.30 Yes 4
2026-09-28 04:00:00 9.35 7.72 0.00 8.35 Yes 1
2026-09-28 06:00:00 9.26 7.72 28.18 8.27 Yes 4
2026-09-28 08:00:00 9.29 7.71 22.14 8.30 Yes 4
2026-09-28 10:00:00 9.39 7.73 0.00 8.39 Yes 1
2026-09-28 12:00:00 9.38 7.75 0.00 8.37 Yes 1
2026-09-28 14:00:00 9.35 7.77 0.00 8.35 Yes 1
2026-09-28 16:00:00 9.29 7.78 22.14 8.30 Yes 4
2026-09-28 18:00:00 9.29 7.79 22.14 8.30 Yes 4
2026-09-28 20:00:00 9.26 7.81 28.18 8.27 Yes 4
2026-09-28 22:15:00 9.38 7.92 0.00 8.37 No 5
2026-09-28 23:00:00 9.38 7.93 0.00 8.37 Yes 1
2026-09-29 01:00:00 9.29 7.92 22.14 8.30 Yes 4
2026-09-29 03:00:00 9.35 7.91 0.00 8.35 Yes 1
2026-09-29 05:00:00 9.26 7.90 28.18 8.27 Yes 4
2026-09-29 07:00:00 9.35 7.88 0.00 8.35 Yes 1
2026-09-29 09:00:00 9.32 7.87 0.00 8.32 Yes 1
2026-09-29 11:00:00 9.29 7.89 22.14 8.30 Yes 4
2026-09-29 13:00:00 9.29 7.91 22.14 8.30 Yes 4
2026-09-29 15:00:00 9.39 7.93 0.00 8.39 Yes 1
2026-09-29 17:00:00 9.35 7.95 0.00 8.35 Yes 1
2026-09-29 19:00:00 9.32 7.95 0.00 8.32 Yes 1
2026-09-29 21:00:00 9.21 7.96 38.24

Here are my last 5 days

Ok, I could guess at what some of that means, lol.
You're gonna have to work out how much DKH this data equates to, per day for example. Then assess if the DKH consumption is low enough to make calcium testing variation a likely candidate for your issues. Failing that, is your salinity increasing?

 

[richiero]

Ok, I could guess at what some of that means, lol.
You're gonna have to work out how much DKH this data equates to, per day for example. Then assess if the DKH consumption is low enough to make calcium testing variation a likely candidate for your issues. Failing that, is your salinity increasing?

lol all you have to look at is the dates and the DKH numbers all the other data is irrelevant

 

[Garf]

lol all you have to look at is the dates and the DKH numbers all the other data is irrelevant

I'm not that good unfortunately.

 

[exnisstech]

Are you sure your testing often enough 11-12 a day seems crazy to me but I only test once a week lol.
If I'm reading it correctly it doesn't look like you have any consumption..

 

[richiero]

How much DKH are you consuming each day? Calcium will only decrease about 20ppm for each 2.8dkh consumed, multiplied by 5 days, obviously. When did you start using the new test kit? This can also cause a wobble in reliability of data, along with the inherent wobbles of testing reproducibility.

From 9/20 midnight to 9/21 1400 hrs the dkh dropped from 9.32 to 8.92 in 14 hrs then I turned the dosers on b/c it was getting to low

 

[richiero]

Are you sure your testing often enough 11-12 a day seems crazy to me but I only test once a week lol.
If I'm reading it correctly it doesn't look like you have any consumption..

My automatic alkalinity tester test my tank every two hours lol

 

[richiero]

Are you sure your testing often enough 11-12 a day seems crazy to me but I only test once a week lol.
If I'm reading it correctly it doesn't look like you have any consumption..

On my automatic tester, it is set up to keep my alkalinity between 9.3 and 9.5 so whenever it test and it's below to 93 it doses, the alkalinity to keep it back in range. That's why it looks like there's no consumption.

 

[Randy Holmes-Farley Verified Community Expert]

From 9/20 midnight to 9/21 1400 hrs the dkh dropped from 9.32 to 8.92 in 14 hrs then I turned the dosers on b/c it was getting to low

So one would expect a calcium drop of less than 3 ppm during that time, and it will be swamped by small changes in salinity.

i think you just have a slow expected rate and cannot reliably detect it with a calcium kit.

 

[richiero]

So one would expect a calcium drop of less than 3 ppm during that time, and it will be swamped by small changes in salinity.

i think you just have a slow expected rate and cannot reliably detect it with a calcium kit.

I'm also going to space my alk testing out to every 6 hours

 

[Randy Holmes-Farley Verified Community Expert]

Sounds like a fine idea. :)

 

[MNAquariums]

I take it the main issue is that everything has been going smooth until recently and the demand for ca and mg slowed down? Do you measure anything else more than the big 3?

 

[richiero]

I take it the main issue is that everything has been going smooth until recently and the demand for ca and mg slowed down? Do you measure anything else more than the big 3?

No haven't done an icp in a while