Alk, Calcium and Magnesium Low

Randy Holmes-Farley · Jun 15, 2016

ENARP said:
I use Red Sea Reef Pro Salt (I shake up the bucket before I use it) and Salinity is 1.026. I was using Brightwell Magnesium Supplement, but stopped during all this testing. I am going out of town this weekend and there is a good aquarium store near where I will be. Any recommendations on products I should look for to correct things?

Ordinary baking soda from the grocery store for alkalinity, and either magnesium chloride or magnesium chloride plus Epsom salt from a drug store.

The magnesium chloride can be obtained from BRS or Dr Foster and Smith.

Or you can buy a commercial magnesium additive (there are many brands), but it is not likely any "better".

ENARP · Jun 15, 2016

Since the test kits and test methods (along with the individual conducting the tests) seems to be the biggest areas of concern regarding the accuracy of my water quality evaluations, is there one brand of test kits or specific method for testing that is recommended by the experienced reef keepers over other kits and methods?

In my testing, I seem to be getting consistent results. I am going through exactly the same process each time. I have followed the instructions to the letter and made sure each test was done consistently and correct to the instructions. I would be more agreeable to questioning my test kits and methods, if only one test showed lower than normal values. With all 3 tests showing low values and those low values being constant and the results of each test almost mirroring the last, I still have some reservations that this may be a testing problem. Just my 2 cents...I will soon be off to the Drug store to buy Baking Soda, Magnesium Chloride and some C9H16O2......

FlyinBryan · Jun 22, 2016

Just be careful with Kalk, watch your Mg a little more closely as it has a tendency to deplete it faster than normal utilization.

Randy Holmes-Farley · Jun 22, 2016

FlyinBryan said:
Just be careful with Kalk, watch your Mg a little more closely as it has a tendency to deplete it faster than normal utilization.

Maybe. I'm not convinced of this, but it does add calcium and alkalinity without adding any magnesium.

ENARP · Jun 22, 2016

I visited a great store last weekend. After discussing my problem they recommended I try Reef Fusion 2 part. I started with 25% of the recommended dose for my size tank . I tested after one day and there were no changes in levels. I have up'd last night's dosage to about 50%. I will do a water change tonight and probably test water tomorrow. I have noticed that all my corals seem to be opening up more.

Randy Holmes-Farley · Jun 23, 2016

If you use this calculator and use the entry for Randy's Recipe #1, and multiply the calcium (or alkalinity) rise by 2.7, you can see the expected effect of that product (Seachem Reef Fusion).

http://reef.diesyst.com/chemcalc/chemcalc.html

FlyinBryan · Jul 12, 2016

Randy Holmes-Farley said:
Maybe. I'm not convinced of this, but it does add calcium and alkalinity without adding any magnesium.

I've seen it. In fact BRS has a mg mixture just for Kalk users. Since then I've been able to maintain consistent levels for longer periods.

Randy Holmes-Farley · Jul 12, 2016

FlyinBryan said:
I've seen it. In fact BRS has a mg mixture just for Kalk users. Since then I've been able to maintain consistent levels for longer periods.

Yes, that is likely my recipe as well:

Do-It-Yourself Magnesium Supplements for the Reef Aquarium by Randy Holmes-Farley - Reefkeeping.com
http://reefkeeping.com/issues/2006-07/rhf/index.php

ENARP · Jul 17, 2016

Have been adding 2 part daily for 2 weeks. Tested Alk today ( 2 times with Hanna Checker) and it was at 60 ppm = 3.354 dkh. So I went to the Reef Chemistry Calculator page. Did calculations for raising Alk using Baking Soda and a 40 gallon water capacity to achieve a level of 7 dkh. Calculator said to add 3 1/2 tsp of Baking Soda. I diluted this into 1 qt of RODI and am currently dripping it into tank at 7 drops per minute. I did not see on the calculation page an amount of RODI to use. I will let this drip overnight and check Alk again tomorrow evening. I hope this is the correct way to introduce the solution to the tank.

Randy Holmes-Farley · Jul 17, 2016

Before you dose that much, double check the testing. Alk rarely can actually drop that low no matter what you have dosed or not dosed.

ENARP · Jul 17, 2016

Ok Thanks

Randy Holmes-Farley · Jul 18, 2016

Let us know what you find.

ENARP · Jul 19, 2016

Did two more Alk tests tonight with Hanna Checker. First test was 56 ppm / 3.131 dkh. Second was 59 ppm / 3.298 dkh. So I am at a loss. Any suggestions on a new Alkalinity Test kit to purchase?

cjd · Jul 20, 2016

I am using red sea alk test kit with good results. I really cant see the alk of newly made saltwater mixing at 8.3 with your salt choice. So I am going to say that your reagent is bad and not giving you accurate results. I am far from a reef chemist but when alk drops too low your tank will stop consuming it and it will just hang out at that number usually in the 6.dkh range. If your cal is within range and mag is within range ,I would say your readings are 3.+ off for alk. I would just try and keep whatever your alk is reading stable and order up another test kit and see what you get. Sorry for your troubles , but I think your chasing inaccurate test results. Its a good idea to have a couple different test kits on hand to double check your test results and other test kits. The kits we use for the hobby are far from "lab" grade and no matter how careful we are with our testing techniques results are usually different from one test to the next. I like to keep my alk at 8.5dkh. I doubt that my water is truly 8.5 but its a good middle road for inaccuracy that a over the counter test kit can provide. Also when I buy a new reagent , I like to test my water once with the older reagent then with the new reagent and compare results. I can say in my 15 years of reefing I never had a dramatic swing in difference , but had a slight difference and if I am certain that the results are accurate enough for that new test kit , I shoot for that new number as my new stable base.