Mg, Ca and Alk are low. Where to start?

[udsmkh]

Hi,

I have a fairly new tank. I measured the parameters the other day and noticed some things out of spec.

Mg 1020 ppm
Alk 6.94 dKH
Ca 339 ppm

I have the things I need to raise each of these parameters but should I correct them in any particular order (i.e. Mg then Alk and then Ca) or correct them all at once? Thanks in advance for any feedback.

 

[Pete polyp]

I would suggest raising the magnesium first because it will keep the calcium and alkalinity from precipitating when you raise it. Once you get the magnesium up to 1300ppm or so it would be safe to add the calcium. After the calcium mixes in the system you can go ahead and raise the alkalinity.

 

[Cment]

What brand of salt are you using? Before you start adding are you sure these are your numbers? Ran multiple test, confirmed with another brand test kit or your LFS? If you have I would take it slow and begin with your mag since it will effect alk. Once you get mag where you want then you can add the others to your desired levels. I would not add ca and alk at the same time, make sure to spread them out.

 

[Randy Holmes-Farley Verified Community Expert]

Hi,

I have a fairly new tank. I measured the parameters the other day and noticed some things out of spec.

Mg 1020 ppm
Alk 6.94 dKH
Ca 339 ppm

I have the things I need to raise each of these parameters but should I correct them in any particular order (i.e. Mg then Alk and then Ca) or correct them all at once? Thanks in advance for any feedback.

What is the salinity and how did you measure it?

If it is low, it would explain all of these being low.

 

[udsmkh]

Thanks for the help, everyone!

What brand of salt are you using?

I'm using Instant Ocean Reef Crystals. I'll double check all the test results.

What is the salinity and how did you measure it?

The salinity was a bit low. I measured it with a refractometer and it was 1.023. This tank is about four months old. I have just a couple frags in it. I've never added supplements before. I do regular water changes and I had hoped that would be enough. Thanks again for the information.

 

[Randy Holmes-Farley Verified Community Expert]

Have you supplemented anything in the past?

If you have not added anything, calcium and magnesium should not be able to get that low using RC at that salinity, but if you have been adding just alkalinity additives, it might. More likely calcium and magneisum are higher than you think, or salinity is lower.

 

[Downbeach]

IO Reef Crystals should read near: Ca @ 450ppm, Mg @ 1450ppm, Alk @ 13dKH at a SG of 1.026/35ppt. I would get your SG up to 1.026 as measured with a properly calibrated refractometer(using a 35ppt calibration solution, not water), checking your freshly made ASW. Do a few WC's and revisit those numbers before you decide how much, if any, dosing you need to do.

 

[helldiver]

ok the first thing i would do a water change, but test the water you are changing and what the parameters are to see if it is the mix if all is go proceed water change and then test water, with 2 different test kits;maybe too also have a friend test it,
First test I usually test is Mg and the adjust to what you like like I run 1400 but most run 1350,this is the binding agent is why I test first, then wait at least 4 hrs. i wait 24hrs then test parameters again you should notice a difference in CA and Alk readings at this point and then adjust to basic standard parameter reading then you should be fine.my tanks run 35ppt to and make sure your temp is in range 78-80
I anyone has anything to add to this please let me know. You see all these elements have to be a balanced ratio

 

[helldiver]

Have you supplemented anything in the past?

If you have not added anything, calcium and magnesium should not be able to get that low using RC at that salinity, but if you have been adding just alkalinity additives, it might. More likely calcium and magneisum are higher than you think, or salinity is lower.

Good advice from downbeach