Overdosing salt?

[SteveG_inDC]

My calcium and magnesium have been high (550 and 1600) but not alkalinity (7.1) and water changes are not changing these parameters. I've started slowly dosing just the alkalinity of a two-part.

I am starting to suspect my Milwaukee digital refractometer is giving me bad readings and I am changing water with high salt concentration (I'm using Reef Crystals). I zero it out with store-bought distilled water and let it sit for a few seconds to pick up temp. It reads 1.025 when I mix it up. Milwaukees are very popular and cited as reliable, but this unit is quite old (I got it used) and I just used it to test water from two other reefers' tanks, both of whom keep their water at 1.025. It read 1.018 for both samples.

Could overdosing salt cause high calcium and magnesium? If so, why wouldn't alkalinity be high too?

I'm ordering a traditional refractometer and calibration solutions but I don't think the Milwaukee digital has a way to adjust it even it's off, other than using the zero button.

 

[Saltyreef]

I was using a swing arm hydrometer for the longest time wondering why my macros were sky high without dosing.
After i got the miluakee i tested my tank and it was at 1.030.
As the years went on i felt the miluakee wasnt as accurate as some make it sound.
Until i got the tropic marin bulb hydrometer.
The miluakee is dead on.
1.025 on the meter
1.0255 on the bulb.

Try the calibration procedure from the manual and take care that the unit is out of direct sunlight but still picking up ambient light.

Also i noticed the reading is more accurate as soon as you turn it on and squirt the sample inside. without waiting for the temp to compensate to what you think it should be.

Also make sure the dish is wiped clean, ill spray a full dropper of test water in there twice to rinse residual pure water out of the dish which always messes with my readings.

Its way easier than a traditional refracto though.

 

[SteveG_inDC]

I do this routinely. I have a spray bottle of RO/DI for cleaning, a box of tissues, roll of paper towel, a microfiber cloth, and I test every sample 2-3 times waiting different times before hitting the test button. I can get stable measurements, but I can't explain why two separate reefers' water tested low (and by the same amount).

 

[Saltyreef]

What were they testing their water with?
And how did you collect and test?
Do you rinse your collection syringe out 3 times with the test water?
Then test?
If theres the slightest bit of left over pure rinse water in a 5ml syringe it will throw off the salinity reading.
It could possibly be user error.
I do water treatment for a living and i see this routinely on my meters when not paying extra attention.

 

[Sarcazian]

I use Reef Crystals myself and I suspected that my Sybor refr has been off (reads 0 with RO) as of late and I picked up a cheap Fluval hydrometer from petco yesterday to compare as well as some juice. You can see from the chart below IO mentioned increasing Calcium and Mg as the salinity increases, but not mention of Alk.

I also picked up an API Calcium test at the same time and I gave up adding dropped around 520 ppm. Salinity showed up as 37 parts on the Hydrometer and 35 on the refract.

 

[Randy Holmes-Farley Verified Community Expert]

My calcium and magnesium have been high (550 and 1600) but not alkalinity (7.1) and water changes are not changing these parameters. I've started slowly dosing just the alkalinity of a two-part.

I am starting to suspect my Milwaukee digital refractometer is giving me bad readings and I am changing water with high salt concentration (I'm using Reef Crystals). I zero it out with store-bought distilled water and let it sit for a few seconds to pick up temp. It reads 1.025 when I mix it up. Milwaukees are very popular and cited as reliable, but this unit is quite old (I got it used) and I just used it to test water from two other reefers' tanks, both of whom keep their water at 1.025. It read 1.018 for both samples.

Could overdosing salt cause high calcium and magnesium? If so, why wouldn't alkalinity be high too?

I'm ordering a traditional refractometer and calibration solutions but I don't think the Milwaukee digital has a way to adjust it even it's off, other than using the zero button.

Yes, if salinity is high and alk is being consumed, that is what would result.

Could also be test error for magneisium and calcium.

 

[Randy Holmes-Farley Verified Community Expert]

You can see from the chart below IO mentioned increasing Calcium and Mg as the salinity increases, but not mention of Alk.

Regardless of what they "mention", every parameter in seawater (except pH and ORP) rises linearly with salinity.

That does not mean they will stay that way in the aquarium, however.

7 dKH, if accurate and unchanged from the original seawater, indicates VERY low salinity for Reef Crystals.

 

[SteveG_inDC]

Yes, if salinity is high and alk is being consumed, that is what would result.

Could also be test error for magneisium and calcium.

Thanks. Another clue is that I used a bag of salt rated for 50 gallons and added it to a mixing bin filled to the 50 gal mark. It tested at 1.019 sg, similar to the reading for the other two external water samples whose owners tested them at 1.025. I'm starting to think I should use that ratio for my next batch while I wait for a calibration fluids to come in the mail. I tried to mix my own calibration solution according to the recipe and it didn't go well. I used a digital scale for salt and water and 35 PSU solution read out at 6 PSU. I think I am a bad chemist.

I suspect my Ca and Mg are not wrong. Red Sea Pro titration kits with new reagents. Pretty straightforward. If anything, those are lower bound readings. Then again, see above. I am a bad chemist. Alkalinity is rising slowly but that's because I've been dosing it. I test that with both Red Sea and Hanna checker.

 

[Randy Holmes-Farley Verified Community Expert]

You cannot mix salt at 35 grams per liter and get 35 PPT. The reason is that there is a lot of moisture in '
"dry" salt.

FWIW, many folks have problems with the Red Sea magnesium kit.

 

[SteveG_inDC]

You cannot mix salt at 35 grams per liter and get 35 PPT. The reason is that there is a lot of moisture in '
"dry" salt.

FWIW, many folks have problems with the Red Sea magnesium kit.

Awesome. I just learned two new things today. Even though I've read as many of your articles as I can, I still learn a lot of new things by following you and this forum. Can't thank you enough.

 

[Randy Holmes-Farley Verified Community Expert]

Awesome. I just learned two new things today. Even though I've read as many of your articles as I can, I still learn a lot of new things by following you and this forum. Can't thank you enough.

Thanks and you're welcome!

Happy Reefing.

 

[SteveG_inDC]

You cannot mix salt at 35 grams per liter and get 35 PPT. The reason is that there is a lot of moisture in '
"dry" salt.

FWIW, many folks have problems with the Red Sea magnesium kit.

I hope that means my readings are wrong. I just got 1700+ Mg with Red Sea pro titration kit. Where is all that mag coming from? The only thing I’ve dosed is seachem reef fusion 2 (alkalinity).

 

[Randy Holmes-Farley Verified Community Expert]

I hope that means my readings are wrong. I just got 1700+ Mg with Red Sea pro titration kit. Where is all that mag coming from? The only thing I’ve dosed is seachem reef fusion 2 (alkalinity).

I expect that is test error.

 

[SteveG_inDC]

I expect that is test error.

If so, I'm getting correlated errors over time. I follow the instructions to the tee with a timer (which include ridiculous steps like shaking for 15 seconds after every drop of reagent A). Does this mean I should throw the test in the trash and find another brand? I went to Red Sea tech support and gave them lot and exp. numbers. Let's see what they say. By the way, their form asks if I wash vials with RO and acid every time. I feel like I spend hours testing parameters. No wonder people shell out big bucks for auto-testers.

 

[Randy Holmes-Farley Verified Community Expert]

If so, I'm getting correlated errors over time. I follow the instructions to the tee with a timer (which include ridiculous steps like shaking for 15 seconds after every drop of reagent A). Does this mean I should throw the test in the trash and find another brand? I went to Red Sea tech support and gave them lot and exp. numbers. Let's see what they say. By the way, their form asks if I wash vials with RO and acid every time. I feel like I spend hours testing parameters. No wonder people shell out big bucks for auto-testers.

Maybe don't bother testing magnesium at all. It is not needed in a newer tank, and it takes a long time for it to get depleted substantially.

I do not know what the issue is, but the Red Sea kit seems to be the source of more than the usual numbers of test issues for magnesium. In a number of instances, folks have tested their water with several magnesium kits, and they have more often found the Red Sea is an outlier than the other kits.

 

[Saltyreef]

I only prefer red sea for phosphate. (Good color differential for a low range kit)
Everything else i test, i use salifert.

 

[Uncle99]

If so, I'm getting correlated errors over time. I follow the instructions to the tee with a timer (which include ridiculous steps like shaking for 15 seconds after every drop of reagent A). Does this mean I should throw the test in the trash and find another brand? I went to Red Sea tech support and gave them lot and exp. numbers. Let's see what they say. By the way, their form asks if I wash vials with RO and acid every time. I feel like I spend hours testing parameters. No wonder people shell out big bucks for auto-testers.

Yes, I did throw that RS MG kit in the garbage.
I replaced with Salifert and have been happy for years now.

 

[SteveG_inDC]

I'm starting to believe the "Red Sea Mg test is garbage" theory. The customer service rep tried to blame it on my not rinsing the glassware in an acid bath. I started doing that and still get weird readings. Granted, the high readings were probably due to running super-high salinity (from using a bad refractometer) and the low readings were from frequent water changes with RO/DI to bring down the salinity. But still, these readings look suspicious to me. It dropped 320 ppm in two days??

 

[Saltyreef]

I'm starting to believe the "Red Sea Mg test is garbage" theory. The customer service rep tried to blame it on my not rinsing the glassware in an acid bath. I started doing that and still get weird readings. Granted, the high readings were probably due to running super-high salinity (from using a bad refractometer) and the low readings were from frequent water changes with RO/DI to bring down the salinity. But still, these readings look suspicious to me. It dropped 320 ppm in two days??

Thats a lot of drop in 2 days for mag. No matter how high the demand!

 

[Randy Holmes-Farley Verified Community Expert]

It's obvious the reading is not correct. Real magnesium consumption is 0-2 ppm in a day. lol