Sweet, thanks for the insight.

As far as I remember, the tapwater in my area, SF Bay area is very soft, so you are probably right, I need to bump up my gH a bit more when I change the water. I'll try to calculate out a dosage based on your recommendations taking into account the ratio of Ca to Mg in Barr's gH Booster. To solve this curling problem, what level am I shooting for? You mentioned even 20ppm is low.

The only reason that I keep tossing in the Bicarbonate to boost the kH is because is to keep the pH from dropping too low if I neglect o to change the water weekly, but you are probably right, i should adjust appropriately when I change the water.