Here is what we recommend.
1) Get an API GH and KH Test Kit and figure out what your carbonate levels are.
2) If you are above 4 dKH, then you should be fine for now but be sure to retest weekly as part of your normal testing regime. Remember that as your system matures, it will create more and more nitric acid so your KH levels will drop over time.
3) As you approach a dKH of 4 or lower, we recommend adding potassium bi-carbonate (AquaBuffer) to your system at a rate of 2 ½ teaspoons (12 ml) per 100 gallons of system water for each dKH level you need to go up.
What if I used half potassium carbonate and calcium carbonate? I know my ph will increase but I’m not sure by how much. Ph 7.8 and KH 53.7.
Julius, Thanks for your question, we do not recommend using both a potassium and calcium base at the same time. Doing so can prevent the uptake of one versus another; the same effect occurs with the addition of Iron and magnesium, as all four of these elements are positively charged ions or cations. We recommend waiting at least a day between a different nutrient amendment to allow the nutrients to dissolve fully, and not interact with each other. I hope this helps! -Joe