I know enough about ORP to know that I do not fully understand it. And that I don't need to really track it constantly. With that said, within the past few days Apex has reported warnings because ORP is above 450. Does a pattern of it rising mean anything? The only thing I have noticed is that my mushroom is shedding; my assumption. I am battling nitrates (17) and Phosphate (. 12). The Phosphate issue has been on going for months. Nitrates have risen in the last few weeks.