Mg vs Ph

your gonna need a chemical engineering degree for this one
why does Mg lower pH?

 

Mag in and of itself doesn't lower your ph but low Mag levels will cause your alk and calcium to drop which will lead to low ph.

 

no disrespect intended, but i hate to disagree with you, just adding Mg to aquarium water or a sample of aquarium water will lower the pH, try it sometime. i had to do it a couple times, couldnt believe the results, mind boggling.

 

Heh... Do you know what are you adding ?! You are not adding Mg, but Mg containing soluble salt. The most probable salt is magnesium sulfate. The sulfate itself can contribute to the alteration of pH. Please be more specific!

 

prior to posting this thread, so not to waste anybodies time, ive added ionically balanced Mg and straight Mg to saltwater samples ( Ca 460, dKH 6, pH 8.22 ) and both give off the same results ( pH 8.19, pH 8.17 respectively).

 

what your saying makes sense, now how to counter act the reaction? and what about the binding of ions?

 

The reaction between calcium and sulfates leads to formation of calcium sulfate that is well known as?! gypsum

In other words, to counteract you need to have reasonably high dKH + some excess of calcium in your marine water. Please notice that sulfates are integral part of natural marine water and they should be present as a free (unbound form). Please refer to this site. Therefore I advise elevating dKH and then adding magnesium mixture. Elevated dKH will have buffering effect, you will notice only marginal drop after addition of magnesium sulfate. BTW what is the brand and name of your magnesium supplement ?!

Cheers!

 

i use kent liquid ionically balanced Mg. right now my tank parameters are salinity 1.026, Ca 500, dKH 15, Mg 1500, Sr 40. pH was 8.22 prior to adding the liquid Mg afterwards it was 8.19. which sparked an interest since i never paid attention to it until today.

 

How do you measure your pH?! What is the temperature?! This is important!

 

calibrated pinpoint pH monitor ( i have 2 both read the same )
temp is 27 c