Anyone not dosing? Just waterchanges?

[ReEf BoSs]

Questions my new tank will is mostly rbta's and mushrooms. There are also a greens birdsnest , pokerstar monti, yellow tipped frogspawn and a war coral.
Wondering if anyone gets away with just doing weekly or bi weekly or monthly waterchanges for dosing alk, cal ,mag ?

Total system water after rock etc is around 20 gallons, so a 50% water change would be no problem. I guess the concern would be the swing in alk or cal hurting corals I still have. Slow growth on lps, sps isnt a concern. Worst comes to worst i will part with some of the sps,lps
i will have to test to see over the long term if water changes are enough just wondering if anyone does it.
Thanks