So I just got a pinpoint PH probe, I’ve calibrated it 3 time now. It reads 7 and 10 perfectly but I don’t trust it’s reading on my tank water. It says my tank is at 7.8 despite the fact I’m using a recirculating CO2 scrubber. When I use my Red Sea PH test it shows 8.2-8.4 pretty consistently. So who do I trust? A chemical test or a probe?