My tapwater has a ph of 7.8, if I slowly discontinue using my ph regulator and gradually adjust my tank ph from the current 6.5 to 7.8 will my silver arowana be ok?? Given that I always keep my nitrate levels below 20 ppm, will it be safe to eventually add a motoro stingray to water with a ph of 7.8?? Anybody with experience please advise.