ORP levels are down and high fluctuation

[Coral_Coco]

Hi everyone,

I've been having some trouble with ORP levels. No fish are in the tank, just corals, a few snails, and a collector urchin. The tank is about 200litrs and I used to run it as an open system until 4 months ago when my live feed pump died and it has been a closed system since then. Orp levels were around 500 and 400. It has gone down to 70/60 but it spikes up to 300s and goes back to 70s again. Can someone give me hand?

 

[Timfish]

Well. microbial processes will certainly be a major part of the fluctuatons as the nutrient cycles have certainly been significantly altered. But that's kinda stating the obvious. What are you doing for maintenance daily, weekly, monthly? Is there a correlation with water changes

For an example of how much microbial processes can change even in a well mainteained and monitored system see this study done att the Georga Aquarium

https://journals.asm.org/doi/10.1128/aem.00179-18

 

[Randy Holmes-Farley]

Sounds like a testing error issue to me. I’d just ignore it unless you are adding ozone.