Hi, hope someone can help. My marine tank was testing out 8 ph and has risen to 8.4 which is the very top end that is safe for the puffers and blenny in residence. Since I last tested PH I have conducted the first water change, just a small one of under 20% with the same seawater that was originally put in to set up. I also added an iron supplement for the macro algae as per bottle instructions (Seachem Flourish Iron). I must add that I have not been able to buy a reef master kit as yet and this is essentially a FOWLR tank apart from some mushroom polyps that hitchhiked and are doing well. I am not at this point checking more than the perimeters needed for the fish's health and am using a liquid test kit meant for freshwater for nitrate, nitrite, and high range PH. It was giving me a false positive for ammonia (and the vial was going cloudy for that one) so I'm using a salifert kit for that. Those perimeters are good, no ammonia or nitrite, nitrate under 5. Should I buy a marine specific PH kit before getting too worried about results? If still coming up high what is the best way to lower without shocking the fish? Many thanks!