I have ordered an octopus calibration kit from the States for my ACIII Pro controller. Your controller is factory calibrated and you'll only want to calibrate it if
a) You wanted to calibrate for a different probe
b) You feel better if you believe the readings will be more accurate calibrated by yourself.
Marine depot link
After paying some high shipping price and a long wait, it's finially here. The kit is very simply, it is some ph 4 and ph 7 calibration fluid and some Quinhydrone. Because Quinhydrone is so hard to find anywhere online and I was desperate, I bit the bullet and ordered it.
Not sure what to expect when I placed the order but I just finished calibrating my probe and I've only used may be 5-10% of Quinhydrone that came with the kit. I'd say the kit probably came with enough Quinhydrone for 15 calibration and I'm thinking of making 4 portions of Quinhydrone and only keeping 1 for myself. I'm selling each portion at $17 without any PH solutions (Can be picked up at any LFS) or you could buy one portion with one PH4 and PH7 calibration fluid for $20.
Your expectation should be purchasing this for 1 calibration but if you play it carefully like I did, you probably will have enough for at least 2 calibrations.
This is only needed if your ORP meter uses a 2 point calibration like the Neptune system or the Octopus controllers. I'll be dividing them in 4 portions and buyers can come and choose which one they want, I'll be keeping the portion that is left behind. Send me a PM if you have any questions.
Steven