high mag low ca

Just tested for CA and Mag for the first time since set up 4 months ago. Used the Red Sea Pro kit
Alk 9.2
Ca 350
Mag 1400

Not sure how accurate the numbers are I followed the instructions on the kit which said when filling the titration syringe there would be 1-1.5ml of air between the plunger and test reagent however it was more like 2cc of air.

How do the numbers look I know the Ca is a little low and the Mag a little high, this is a non sps system

 

Those are pretty good. The Ca you want to keep between 380 and 450. For LPS and softies they should be fine. The Mg is really not much out of line. For SPS just get the CA to the range I stated.

 

So if I only keep softies and a few lps a CA of 350 will be good enough? I decided to test because my acan frag still has not opened up (I purchased 2 that are different colors but both acans) and 1 opened up within a few hours and sends out its feeding tentacles at night and the other has remained closed up

 

IMO

repeat the test , if it is a new kit and one you have not used before
there is often variation due to unfamiliarity, and we do not want to take drastic action to cure a problem that may in fact not exist

if the numbers are accurate
the calcium is a bit low but not concerningly low in a softie set up IME 380 would be a good base line - somewhere between 380 and 450 would be fine IME
the Mag is OK at 1400 and will help to hold a bit more calcium without adversely affecting your DKH
The DKH is also fine as it is

 

So does increasing CA decrease Mag?

 

increasing Calcium, could cause other ions to fall out of solution
in general the ions that are forced out are carbonates (alk or dkh)
this normally happens if the Mag level is not high enough to support them all in solution

think of magnesium as a binding ion, in that it can help keep the ratio of calcium and alkalinity ions in solution for you

thus having 1400 ppm Mag if that is the case, means you will not have any issue increasing your calcium (if you in fact need to) from 350 - 390 ( only increase by 40ppm in any 24 hour period, in order not to shock inhabitants, you could do more, but there is no valid reason to do so IMO)
then 24 hours later you could go up again from 390 - 430 , and maintain it there and you are golden IME

Steve

 

No it does not, it can decrease alkalinity though so be prepared to add a little alk if like where it is at. The higher Mg will help with stability of the Ca and Alk. Do not add CA and alk at the same time, add them at least an hour apart, as they react and precipitate out and not do you any good.

I agree with running the tests again to familiarize yourself with the kits and how to perform the tests.

 

I will be repeating the test somewhat often until I am getting pretty similar results from day to day and trust my results before doing anything drastic. Right now all I have is marine buffer and balance by seachem so if I need alk or CA I will have to go purchase some products. Does anyone use seachems aquavitro line or do other products come more highly recommended?

 

I haven't used the line but it supposed to be very good and is quite pricey. If you intend to stay with the LPS and softies then it would be a good investment.

 

It is a little pricey but for a 46gallon tank you dont go through too much that it becomes a burden. Now when I set up a larger tank like some of you have where you have 200+gal systems then it may become an issue lol