how to maintain cal, dKH, mag in 29g biocube

[cheezefrog]

I have had my tank up for a few years now, roughly its a 36g system w/ custom sump.

My stock list is piling up, sps, lps, softies and coraline algae has really exploded in recent months. My trace elements are getting soaked up pretty frequently now where my routine 5g weekly water changes wont suffice.

The water changes balance my levels back to normal(after weekly dosing prior to the wc), but in 3-4 days I'm seeing my levels drop from:

Cal 420ppm

Alk 7.9-8.1dKH

Mag 1320-1350ppm

To:

Cal 410-400ppm

Alk 7.0dKH

Mag 1290ppm

Although calcium seems to be dropping randomly, it'll stay constant at 420ppm for a good 4-5 days even a week and then just abruptly drop to 400ppm at random.

I have a hard time trying to maintain alkalinity and mag though, and planned on picking up some 2 part esv with an auto doser, but dosing doesn't seem practical and to expensive at this point. Since the buffer or target alone for raising magnesium from 1290-1320 is almost 108mL! seems like thats too much for such a small tank in my opinion.

Should I go with kalkwasser solution and if so could someone recommend which brand/product. Will any of them raise and sustain equal levels of Cal, Alk, Mag that I'm trying to target for? Is there hardware upgrades I should look for? Pretty limited to space and scale of things.

Looking for opinions as I'm trying to really keep everything constant at these water parameters:

Cal 420ppm

Alk 7.9-8.1dKH

Mag 1320-1350ppm

[ghostgr]

Id say do your water change so its at your before numbers then dose as needed to maintain said numbers frequently.

[reefernanoman]

I never dose anything in my 28G Nanocube. I never test for any of that stuff either. My corals grow big and happy with 3g weekly water changes. Why complicate things so much in such small tank? Same thing for my fusion 10g(1 gallon weekly water change with beautiful corals).