[globaldesigns]

Hello Barthsimson, welcome to canreef!

In regards to your problem, usually MG and KH are not related, so are you talking about trying to decrease your KH also while trying to raise your MG? Also how old is your system?

While tailored aquatics is good, I found it too expensive for what it is... And some LFS (no names mentioned) charge way too much for it. I personally use SeaChem MG crystals from jlaquatics.com. A 2.2KG of crystals is only $23 and treats over 2,500 Gallons, so it would last you some time.

I would use the above mentioned for your MG requirements... Remember that Strontium is also an element that needs to be replenished and runs hand-in-hand with MG... I don't personally test for Strontium, but if my system needs MG, I dose Strontium also as required. Seachem also has Strontium crystals (1KG) for $13... This will do 5,000 Gallons. If you don't have coral, you really don't need to supplement MG or STR.

In regards to your KH/PH problem, your parameters look good overall, except for MG (of course), but I notice your PH is low also... PH and KH do work together and raising your PH to a proper level of 8.3 should help to lower your KH level to acceptable levels. I run my KH at 7-8, but I run Zeovit, most others may recommend 10-12 KH for non-Zeovit systems. Usually if your PH is in check your KH will be also, but if not then you can supplement to raise or lower that, but I would work on your PH levels before tackling your KH.

Before buying anything to alter your PH, try doing some water changes, say a couple over a couple days of about 15-20%... Then give it a day and take another test reading of your PH and KH, hopefully things settle to acceptable ranges with water changes only.

I hope this helps.