ORP Calibration Fluid - 225mv?

[bdare]

Hello all,

This week I added an ORP probe to my tank. Been having some weird issues so I added an ORP probe hoping it might provide some clues. My question is why does GHL use the 225mv calibration fluid? According to @Randy Holmes-Farley most aquarium authors recommend a value of 300-450 (http://www.reefkeeping.com/issues/2003-12/rhf/feature/index.php). In addition, all other ORP probes that I've seen use a calibration fluid closer to the values recommended by Holmes-Farley (400mv).

Can you tell me why GHL recommends 225? Is there any harm in calibrating my probe with 400 solution?

At the end of the day I don't think it matters tremendously as I'm just trying to correlate incidents in my tank that make it rise or drop, but I am very curious.

Thanks,
Ben

 

[Lasse]

IMO - you decide by your self when you configure the calibration. But - I do not know if GHL accept 400 - have not tested

Sincerely Lasse

 

[Member No 1]

I will add, before you calibrate the ORP probe, allow it to stabilize in the sump for a few days. I always wait a week. Seems unlike a pH or conductivity probe, it needs to soak before you calibrate them. Not 100% sure why, just my findings.

 

[bdare]

@Vinny@GHLUSA - Can you tell me if the GHL controller will allow me to calibrate my ORP probe using 400mv solution?