ORP falling during lighting cycle

[polywise]

Why is it that about a hour or so after my lighting turns on, my orp reading begins to decrease? It does this very day around the same time frame.

 

[InfernoST]

As your PH increases from the lighting your ORP will decrease.

 

[greg 45]

This is normal

 

[NYPDFrogman]

it is normal fish are less active in the dark when the lights are on they are out and about swiming so they use more O2 during that period
they also poop to while swimming
dont get too hung up on the numbers everyone's tank is different
look for stability my ORP usually swings 20-30MV during the day

 

[naples]

Here is a very good link about ORP

http://reefkeeping.com/issues/2003-12/rhf/feature/index.php

 

[polywise]

Eric, I will read when I get a chance.

I know swings are normal, just feeling I am seeing more than expected.

Jim C.