0 ORP level

[GSnake]

Hi,
I got a new ORP pen tester, and my orp ranges from -59 mv (night( to 0 MV (day).
I run ozone in my recirc skimmer and got the pen for that, but I was expecting more than 0.

No decaying animals here, but I do have some sand bed cyano since I dosed and stopped using vodka/vinegar. Im hoping the ozone might get rid of it?

Water clarity has increased since ozone use, no more yellows, but I'm wondering about average tank range vs my readings.

 

[Sisterlimonpot]

Does the orp pen come with calibration instructions?

Can you share more information on what type of pen it is?

 

[GSnake]

Ble-c600 pen with Bluetooth. It's a 6 in one type. The manual only came with pH and EC/TDS/ salt calibration instructions, though I imagine the procedure is the same for orp. While the unit only came with pH buffer calibration powders.
I tried the pen on some h202 and water in a cup and it shot up to 350mv. Seems functional. Is there a diy calibration solution with h202/water.

 

[GSnake]

My reading from this morning

 

[gbroadbridge]

Ble-c600 pen with Bluetooth. It's a 6 in one type. The manual only came with pH and EC/TDS/ salt calibration instructions, though I imagine the procedure is the same for orp. While the unit only came with pH buffer calibration powders.
I tried the pen on some h202 and water in a cup and it shot up to 350mv. Seems functional. Is there a diy calibration solution with h202/water.

You would have to purchase a calibration fluid for ORP, I don't know of any DIY.
However, it doesn't appear that it can be calibrated.

If the pH and EC works, I'd suggest using it just for those as ORP is not really useful except when Ozone dosing.
I would not trust a device like this to control Ozone.