A drop of 1dKh/day is consistent with what I would expect from your description of your system. I am getting 1-2 dKh drop/day in all of my tanks. I dose about 750ml of dKh/day total between all of them to keep up. Once you determine how much Ca and Mg you need to add for every 1 dKh, you can just test dKh and add the appropriate ratio of each. Then it's just a matter of testing for the others much less often.
Dan
PS-Typing on the computer now .
Thanks Dan
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You wouldn't want to see my tank. I don't use fancy equipment and I am a noob