I've contacted AP, but over a day now and no response. I've called the tech support line, left a message too.
I'm really curious about this - my nitrate readings are low enough that I'm showing a clear ZERO when I hold the tube over the card, but 5-10 when held on the card.
I don't want to use the method that gives me the results I want
My pH tests are always right-on when held against the card, but a little low when held away.
180G build thread
180G All-glass with dual megaflows in a custom stand
AquaC EV-180 skimmer
250 pounds LR
160 pounds aragonite
Custom acrylic sump from GlassCages.com
2xPCX-40 return pumps
2x250MH 14K, 2x175MH 14K - PFO lighting, 2x65W PC
No-name 36W UV
Water General 125GPH RO/DI