How is the fishless cycling doing? It has been almost a month. If everything is normal, it should be done or near done by now.
Water PH needs to be tested only after nitrate start to increase. When the water is too acidic, it will slow the growth of the beneficial bacteria required for the aquarium nitrogen cycle. The testing of water PH will let you know when a partial water change is needed. If you see the PH crashes suddenly to 6 or lower, you might want to do a large partial water change of 50~90% to restore the water PH and buffer.
Please let us know how you are doing. Look forward to see another properly set up home aquarium with beautiful fish.