Dosing ALK and Mag

[Connie]

Thanks.. I don't dose calcium. I haven't in a long time, but I do check it twice a week. I am dosing Mag and Alk daily, but I'm not using anywhere near 60 oz. of mag. I don't have a heavy SPS load yet. Do you think I need a dosing pump anyway? I appreciate the help!

Connie if your readings are good this is what I would do. Remember there are a thousand was to get to the end:
First I would stop dosing Ca. Continue to measure for it but let your system use it up till it gets close to your desired level.
Second I would continue to elevate my Mg. Look this up but I don't think you want to elevate it more than 100ppm per 24 hrs. Example my 180 I was dosing 60 oz every 24 hours and this kept me under the 100ppm. (Mg I only check every three months)
Third continue to dose Alk as you have been. Once the Mg is within normal range start adjusting.
Also I've always been told you dose your Alk and Ca exactly the same, for two part.
Lastly I'd look into getting a dosing pump. Let me know if you want one and ill see what I can do.
Good luck and call if you have questions

 

[Connie]

I don't have another calcium test. I threw one away a few weeks ago because it was about 3 years old. I will get another one next time I'm in the LFS. I calibrate my refractometer with Pinpoint 53.0 calibration fluid, and I also use a glass (floating) hydrometer as a back up, so I think its pretty much dead on.

There have been a number of threads on this and other forums about the Hanna Ca checker being both inaccurate and inconsistent. Do you have a different Ca kit to confirm? I would continue to dose the Alk, as long as your Mg is around 1200, you should be fine. Is your refractometer calibrated with a solution that is near the refractive index of the sample you are testing, i.e. 35ppt? If you are using RO water, you may have, whats called a slope miscalibration, meaning that calibrated at '0' with RO water it seems right on, but it could be way off at 35ppt/1.026. IF, your refractometer is misleading you, it may be as simple as getting your SG in line, and your Alk and Mg along with it.
Here's an article about that:
Refractometers and Salinity Measurement by Randy Holmes-Farley - Reefkeeping.com

 

[mike007]

Your ca level will come down with your regular water changes. Keep a eye on your alk. it will probaly be low with a high ca. level. You also might want to double check your water parameters with another test kit or take a sample to your lfs. My ca level got really high and i did nothing and it came down on its own. I never have added anything to bring my mag. level up. Be carefull and don't start adding stuff to correct the other. Most salt mixes have everything needed.

 

[Connie]

OK, so.....I bought a Seachem Calcium Test as a back up to my Hanna Checker. The Hanna reads over 600. The Seachem test reads 450. I tested with each tester twice to make sure they were consistent. Can the Hanna be off that much?!