Help needed - Alk @ 7.2 dKH but Ca and Mg extremely high

[JFD]

Hi all,

I use a calcium reactor loaded with Rowalith W and do not dose any other form of Alk, Ca and Mg.

My levels (according to my last ICP test) are Ca - 514mg/l and Mg - 1632mg/l whilst my Alk, according to my Hanna Alk checker, sits around 7.2 dKH.

I would like to bring my Ca and Mg levels down to adequate levels, however without lowering the Alkalinity levels.

So, can I kindly ask you what would be the viable options? Water changes, stop the CaRx whilst dosing AlK?

Thanks lots....

Cheers!

 

[Randy Holmes-Farley Verified Community Expert]

What is the salinity? Measured how?

Have you dosed those? tested how?

 

[JFD]

Hi @Randy Holmes-Farley ,

Thanks for answering!

So salinity is at 35.2 ppt according to the Hanna salinity tester (I've calibrated it to provide this answer).

I haven't dosed any Alk, Ca or Mg, it is all coming from my calcium reactor that has a set pH range of 6.2 to 6.3 (according to the manufacturer of the media this is the recommended range I believe).

I use this media: www.Rowalith W


The Ca and Mg were ICP tested and the Alk I used my Hanna Alk checker to measure it...

Let me know of any other question if you need...

Cheers,
Jose.

 

[Dr Jimmy]

I used baking soda to correct my lower alkalinity. Not sure if that's the solution for you, as I'm still learning how to keep corals.

 

[Randy Holmes-Farley Verified Community Expert]

I'm not sure how you get to those levels of calcium and magnesium except by high salinity, high levels in your salt mix, or test error.

I'd start off by testing your salt mix.

 

[JFD]

I'm not sure how you get to those levels of calcium and magnesium except by high salinity, high levels in your salt mix, or test error.

I'd start off by testing your salt mix.

Cheers @Randy Holmes-Farley - much appreciated!

Transparently, I have made 4 ICP tests (for the same sample) and 3 of them pointed out the values I provided on the thread earlier, the 4th (which I only received yesterday evening and being the only one that provides values for salinity and alkalinity) showed completely different values, i.e. Ca = 491mg/l and Mg = 1408mg/l. The salinity analyzed by the ICP lab was 34.85PSU...

These values are also in line with the home analysis I made on the day...


It is interesting, however to see, that the ICP Labs that don't present the salinity analysis are all aligned to high levels of Ca and Mg and the one that shows salinity and alkalinity values present the values I was expecting...

It is puzzling... Now with this being said, I haven't noticed any issues with corals, inverts or fish.

 

[h2so4hurts]

And, how old are your Hanna reagents, and how much is left in the bottle. It spoils quickly. Maybe pick up a Salifert or RedSea to confirm before you do anything drastic.

 

[JFD]

And, how old are your Hanna reagents, and how much is left in the bottle. It spoils quickly. Maybe pick up a Salifert or RedSea to confirm before you do anything drastic.

Hi @h2so4hurts thanks for replying!

Not old, really! I go through 1 bottle of KH reagent and 1 box of sachets of Po4 reagent every month... These ones the expiry date was 08/21... So well within!

So far, I haven't seen any issues with any of the animals in the tank so I will be keeping an eye out....

 

[h2so4hurts]

Mine starts going south around the 1 month mark. Also check consistency with previous batch. I just switched and the new batch is reading 0.2dkh lower. I use salifert for backup just to try to understand if it's just the kit or an actual problem

 

[X-37B]

What are the big 3 numbers including sg of your salt mix?
How often are you doing water changes and how much?
How big is your system?
Send out an icp on your fresh salt water for a reference and compair with your test method.
Retest alk with salifert or another for reference.