Measuring par

[rfgonzo]

When measuring par do you measure with all pumps and powerheads off? or all pumps and powerheads running? Drastic difference in readings. Pumps on can be 50 to 150 less par or more depending on areas of tank.

 

[cvrle1]

https://www.reef2reef.com/threads/first-time-using-par-meter-question.536636/https://www.reef2reef.com/threads/how-do-i-measure-par.349553/https://www.reef2reef.com/threads/par-measurements-pumps-on-off.387625/

 

[happysalt]

I've always measured with pumps and powerheads running. I want to know the real number getting to each of my corals throughout the day as opposed to "what it could be".

My 2 cents...

 

[jda]

It depends a lot on the meter. My Apogee 510 gets pretty close regardless. A Seneye will have a different reading with still water vs running.

 

[rfgonzo]

I'm measuring it with my Apogee MQ-200

 

[Bpb]

I cut the flow because the shimmer causes the readings to jump around nonsensically. I’ll read between 150-400 and every number between spastically. So I have to cut the flow and hold it still until the number jumping is within 5-10 par