Effects of par when raising a light

[mch1984]

I'm pretty sure I know the answer to this but wanted to check and make sure. I was watching some of the BRS videos and they mentioned raising LED's to help with diffusing the light. I had considered doing a floating canopy anyways and so now I'm thinking I will. Question or confirmation is does raising the lights have any effect on the par? They are maxspect etherals and are only about 8" above the water now, thinking about going around 18". I have plenty of room for it and don't mind them being over the tank like that.

 

[EmdeReef]

It will have some effect on par reduction but without a par meter hard to tell if significant.

 

[Big G]

Do you have a LUX or PAR meter? Would be interesting to check the readings at the water surface as you raise the lights. I use a LUX meter to check for surface coverage in a pattern that covers the entire tank surface. It's interesting to see how and where the light is dropping off and how much it drops.

 

[mch1984]

I don't own one, I borrowed a fellow reefers one time to help tune my lights in. I'm sure I could borrow his at some point. I've also thought about just buying the one for apex, that's the one he had and it seemed to work well.

 

[Big G]

This LUX meter from Amazon works pretty good, especially for the price. Nice to have on hand. Proffs to @saltyfilmfolks for suggesting it.
https://amazon.com/gp/product/B00LSFR0FO/ref=ppx_yo_dt_b_asin_title_o05__o00_s00?ie=UTF8&psc=1

 

[mch1984]

This LUX meter from Amazon works pretty good, especially for the price. Nice to have on hand. Proffs to @saltyfilmfolks for suggesting it.
https://amazon.com/gp/product/B00LSFR0FO/ref=ppx_yo_dt_b_asin_title_o05__o00_s00?ie=UTF8&psc=1

Oh yeah at that would at least give you an idea of what the increased height did to it. Thanks