It is possible you overdosed but im highly betting on a bad test kit. API kits are notoriously inaccurate. 23 drops is absolutely off the charts and i cannot see it being that high at all. Look into getting a salifert alk
test. Very accurate and reliable.
Smart move not accepting right away that 18 and 23 are not correct readings. Ph would most probably be much higher if it were.
29g Mixed Reef, 150w 14k Phoenix MH w/ Moonlights, Reef Octopus BH1000 HOB Skimmer, Ecotech Vortech MP10es, ReefKeeper Lite (Plus), PH Probe, Temp Probe, ATO, Carbon/GFO Reactor.