Alkalinity, Calcium, and Magnesium all testing high?

cjphi14 · Feb 20, 2021

Hi, have had a 55 gallon tank for about a year now, never dosed calcium or anything into the tank before. I've just recently begun testing for Magnesium, Alkalinity, and Calcium with red sea pro test kits. I know they are not all supposed to be elevated. Magnesium is at 1560, Alk at 14 Dkh, and Calcium at 490. Any reason they could be so high?

Stigigemla · Feb 21, 2021

It can be high salinity. Try to get a second measurement from another reefer.

KH many times get high if You use tap water, A kH of 5 in the tap water will increase the kH in the tank with 5.
It might be a good idea to check that Your osmosis is correct connected. A kH test of the osmosis water shall shift color on the first drop. Its not a good test for an RO/DI but good enough to see if it is wrong connected between the stages.

Aqua Man · Feb 21, 2021

Stigigemla said:
It can be high salinity. Try to get a second measurement from another reefer.

Have you calibrated your refractometer lately? Is your tank a reef or fish only?

DaneGer21 · Feb 21, 2021

What salt mix do you use?

cjphi14 · Feb 21, 2021

Measured with refractometer and hydrometer. It’s brand new and I just recently calibrated it. My tank is currently mainly fish I have 2 corals right now. And I also use instant ocean salt mix.

DaneGer21 · Feb 21, 2021

With that salt mix, those numbers are fairly close to what it should mix at.

cjphi14 · Feb 21, 2021

DaneGer21 said:
With that salt mix, those numbers are fairly close to what it should mix at.

Ok thank you. I’m slightly concerned with the alkalinity but I think a water change should do the trick.

BigD9.5 · Feb 24, 2021

Lfs is closed today...bummer,definitely tomorrow

Jekyl · Feb 24, 2021

No salt mix has alk that high. I use coral pro which I think is the highest at around 11

Randy Holmes-Farley · Feb 24, 2021

Normal IO and Reef Crystals are 11-13 dKh, typically, unless they have been stored and suffered precipitation of calcium carbonate.

Aqua Man · Feb 24, 2021

Bucket of reef crystal I’m on now is 11.3 dkh

cjphi14 · Feb 24, 2021

Randy Holmes-Farley said:
Normal IO and Reef Crystals are 11-13 dKh, typically, unless they have been stored and suffered precipitation of calcium carbonate.

Hmm... thats odd. I did a 50% water change and no change in alkalinity. Not sure if that is normal or not. but calcium and magnesium are normal again. What would the precipitation of calcium carbonate do?

Randy Holmes-Farley · Feb 25, 2021

cjphi14 said:
Hmm... thats odd. I did a 50% water change and no change in alkalinity. Not sure if that is normal or not. but calcium and magnesium are normal again. What would the precipitation of calcium carbonate do?

When you combine 50% of solution A and 50% of solution B, the alkalinity will be the exact average of the two values before mixing.

I'm not sure what the alk values were before or after mixing in your situation.

precipitation of calcium carbonate lowers alk and calcium in the ratio of about 2.8 dKH for each 18-20 ppm of calcium decline.

Afaylenerich88 · Apr 22, 2021

I would bring your dkh, down. The rest is okay but you gotta get that down somehow. I'd mix your water 3 days in advance and let the dkh fall off then test. Bring to level you need you might not have to do anything. Then start doing 50% water change then 3-4 days later do another. Then I'd do 20% weekly. Then finally 10% weekly. Should stabilize your tank but keep an eye on it. 14 is way to high, 12 is the line of success. And your over the edge. I keep my tank at 8 dkh. Also what time are you testing you should test during the mid day, and night time after lights out for a few hours and you should notice your alk drop at night. Unless your dosing alk.

arking_mark · Apr 22, 2021

cjphi14 said:
Hi, have had a 55 gallon tank for about a year now, never dosed calcium or anything into the tank before. I've just recently begun testing for Magnesium, Alkalinity, and Calcium with red sea pro test kits. I know they are not all supposed to be elevated. Magnesium is at 1560, Alk at 14 Dkh, and Calcium at 490. Any reason they could be so high?

The most likely cause is testing. Hobby-grade test kits are prone to error. If you never dosed additives and have used quality salt and RODI water, I find those numbers to be highly suspect.

karamreef117 · Apr 22, 2021

Something to look into. Did you mix up the salt when you opened the bucket? I would ask this since a lot of times elements are all over the bag and they aren't mixed right so you might get a lot of everything. Another thing I would consider is to make a switch to another salt if the levels ar this high it would save you headaches and money in the long run. There is a post and almost everywhere online about salts and what the levels of those salts Are. Red Sea has a great name to it and is a big company but go after the numbers.

karamreef117 · Apr 22, 2021

arking_mark said:
The most likely cause is testing. Hobby-grade test kits are prone to error. If you never dosed additives and have used quality salt and RODI water, I find those numbers to be highly suspect.

That is very true. spot on