I agree with @Leaky Filter
. You may need to boost your fertilization a bit. I think you are dosing according to the Tropica label, but unless otherwise specified, most dosage recs are for low tech tanks.
I bet the calcium addition will help - although if your Ca was that low I would consider Mg as well. Do you have a GH test kit? If you do you can estimate the Mg in the water as GH is mainly Ca + Mg. Normally you want something close to a 3:1 Ca:Mg ratio.
Also, I think you could probably do with more CO2 in your tank. A 0.2 pt drop in pH is not much, to hit 30 ppm of CO2 you would look for a full pt drop in pH given water KH between 1 - 10. Dennis Wong has a good article on optimizing CO2 here: https://www.advancedplantedtank.com/...oosing-co2-why
. You might get some good pointers here.