Seeking help from dosing gurus

[mrhasan]

Well so recently I had to start dosing alk since it would fall to 5dkh otherwise. So my plan is like this:

At morning, the alk is around 8 so I dose 6ml of soda ash mix to get it to around 8.5. At night, it falls to around 7.3dkh so I dose 12ml to bring it up to 8.3. This is a content trend that I have noticed and I am following it.

Alongside, my Ca drops to around 380 before water change so I don't dose anything; just replace Ca to 440ish with WC.

My Mg seems to be going down (its at 1260ppm now) and I have started dosing magnesium mg from taylor aquatics. But funny thing is, it says to put in cap full per 20 gallon daily. Doesn't say how much it will increase. So I dosed a capful and the mg stayed at 1260ppm (tested like after 10mins). I again dosed another cap full and it is still at 1260ppm :O I am confused; does mg takes a longer time to increase or the cap full is just too low?

P.S. I am using salifert to test the big 3.

This testing before and after dosing (alk is now fine) is kinda driving me nuts. I am thinking of moving to 50% weekly WC along with dosing Alk. Testings are making this hobby expensive :S

So I humbly request dosing gurus to help me out with this situation