Trying to balance MG, ALK and CA

My tank is now going on a few months old and I'm trying to get my levels of MG, ALK and CA balanced. I am currently not dosing anything, just doing monthly water changes of about 25% and I'm looking for suggestions of what/how much to dose.

My tank parameters are as follows:

Tank size 180g with about 230g of total water.
PH: 8.1-8.3
Nitrates: <5
Phosphate: 0
Calcium: 440
Magnesium: 1290
Iodine: .02
Alk (KH): 7

My calcium has been high (480+) and has been coming down over the last month. Not sure why it started out so high, original I was using reef crystals but I've just used regular IO salt that last couple water changes. I'm not 100% if it's calcium precipitate that I have floating in my water, but based on what I've read I believe it is. I'm hoping this goes away as the levels get down to around 400.

I'm wondering if I need to raise my MG and KH levels and if so what products should I use to do this? I don't want to use anything that would make my current CA situation any worse.

Thanks for any suggestions

 

Ca should be in the range of 380 to 450ppm, Mg 1250 to 1350ppm and alk 7 to 11 dKH. There are plenty of products out there. Just buy one that is specific to each of the big three. They all do their job so if you can buy whatever your LFS has.

 

Your Alk looks like to little bit low. You might raise to 8-8.5. I keep my at around 8.3-8.5. Your magnesium is OK in the range.