How much does flow affect PAR levels?

[Ian Baxter]

Just did my PAR levels with the VBR-Aqua with no flow on. I have 2 Hydra 32HD 12" off the water. Tank is 36L x 24W x 18H, Saxby settings. The numbers that are underlined are on a surface, the others are open sections. I've read that some people need to multiply their readings with this meter by 1.7 to be the same as Apogee, but others say no. Does this seem accurate?

 

[shakacuz]

the 1.17x is done to make the number match the reading you'd get on the apogee500. always do this considering the apogee is the "hobby standard" in terms of PAR meter. especially the 510.

i believe flow has little effect on PAR unless you are creating a lot of surface agitation. that "disco" effect is what changes the PAR reading but i don't believe it to be significant enough to create a large gap in PAR readings.

 

[Ian Baxter]

the 1.17x is done to make the number match the reading you'd get on the apogee500. always do this considering the apogee is the "hobby standard" in terms of PAR meter. especially the 510.

i believe flow has little effect on PAR unless you are creating a lot of surface agitation. that "disco" effect is what changes the PAR reading but i don't believe it to be significant enough to create a large gap in PAR readings.

Yes, but others say that don't need to and compared it to the Apogee 510. I did post my results on an AI Facebook page and someone with similar settings, height, and depth said they were accurate. But I'm not sure. I might just need to rent an Apogee to find out.

 

[shakacuz]

Yes, but others say that don't need to and compared it to the Apogee 510.

go with what @telegraham says as this comes down from his own research/experience. the 1.17x is so that the VBR-Aqua readings align with the ones from the apogee 500. if you don't, you'll just have readings "close to" what the apogee 500 would measure.

 

[Ian Baxter]

go with what @telegraham says as this comes down from his own research/experience. the 1.17x is so that the VBR-Aqua readings match the ones from the apogee 500. if you don't, you'll just have readings "close to" what the apogee 500 would measure.

Sounds good. I was reading all of his reviews on it and that convinced me to buy it.

 

[jda]

If the sensor is cosign corrected, then it won't matter much. If it is not, then you really need to turn the flow off to get an accurate measurement.

 

[twentyleagues]

Well I cant answer the question about your meter, But I can tell you my observations from my current set up with flow on and off.
At the top of my rock structure directly under my light about 10" under the surface with flow on decent amount of surface agitation I have somewhere between 195 and 207 par. With the flow off its 215 par. This is with a apogee 510.

 

[Hurricane Aquatics]

Just did my PAR levels with the VBR-Aqua with no flow on. I have 2 Hydra 32HD 12" off the water. Tank is 36L x 24W x 18H, Saxby settings. The numbers that are underlined are on a surface, the others are open sections. I've read that some people need to multiply their readings with this meter by 1.7 to be the same as Apogee, but others say no. Does this seem accurate?

The most important question is what are you trying to keep under the measured PAR levels?

I have the ITC PARWise and the Apogee MQ-510 and can answer any questions you might have. I have never dealt with the PAR meter you are using, but I must admit, it looks very interesting.

I would say those PAR readings are very close based on that light fixture and the mounting height. I wouldn't beat your head on the wall trying to get multiple readings. Post what you are hoping to achieve and the livestock you want to keep.

Oh, I forgot to add, yes water movement does affect PAR. Any time light is refracting it will affect PAR. I usually stop my flow and check, but sometimes I check with the flow on. It isn't going to make a big difference one way or the other in your reef keeping with your system.

 

[Ian Baxter]

The most important question is what are you trying to keep under the measured PAR levels?

I have the ITC PARWise and the Apogee MQ-510 and can answer any questions you might have. I have never dealt with the PAR meter you are using, but I must admit, it looks very interesting.

I would say those PAR readings are very close based on that light fixture and the mounting height. I wouldn't beat your head on the wall trying to get multiple readings. Post what you are hoping to achieve and the livestock you want to keep.

Oh, I forgot to add, yes water movement does affect PAR. Any time light is refracting it will affect PAR. I usually stop my flow and check, but sometimes I check with the flow on. It isn't going to make a big difference one way or the other in your reef keeping with your system.

Im looking to have a mixed reef. These are the corals I’m looking to get along with the ones I have that have the green check.

Corals:
Hollywood Stunner Chalice
Red/Green Monti cap
Favia of the Gods
Rainbow Pocillopora
Dragon Soul Torch
Rasta Torch
Hammer
Ultra Rainbow Symphillia
Ultra Rainbow Bowerbanki
Orange Acans
Zoas
Leptoseris
Cyphastrea
Monti’s
Hammers
Blastos
Lobos
Trachy
Eventually I might try some sticks

 

[Hurricane Aquatics]

Im looking to have a mixed reef. These are the corals I’m looking to get along with the ones I have that have the green check.

Corals:
Hollywood Stunner Chalice
Red/Green Monti cap
Favia of the Gods
Rainbow Pocillopora
Dragon Soul Torch
Rasta Torch
Hammer
Ultra Rainbow Symphillia
Ultra Rainbow Bowerbanki
Orange Acans
Zoas
Leptoseris
Cyphastrea
Monti’s
Hammers
Blastos
Lobos
Trachy
Eventually I might try some sticks

The PAR you have listed in your picture should be perfect. It looks like your torch and other corals are doing good. LPS range from 100 to 200 on the high side and as you can see that torch is happy. I wouldn't change the par from where you have it. If you ever need more for any reason, just lower the fixtures an inch or two.

 

[Ian Baxter]

The PAR you have listed in your picture should be perfect. It looks like your torch and other corals are doing good. LPS range from 100 to 200 on the high side and as you can see that torch is happy. I wouldn't change the par from where you have it. If you ever need more for any reason, just lower the fixtures an inch or two.

Thanks for the help!