Par readings

[StephNewman]

I got the par meter today and I my reading are pretty much in the lower 100s throughout my tank. Everything has been happy so I guess these levels are okay but would lowering my halides some to increase par help my coral grow even more? I feel like I am wasting the energy use of metal halides if I am getting that low of par. I just put these Phoenix bulbs in in jan. And the par is high close to the halides so they are producing a high par but it seems to quickly lose par as you drop to the point by the time I even touch the water it is down to the 300s. The halides are 12 inches off the water.

 

[Pife]

What is the wattage of your light? How high are they? What reflectors are you using? How many lights. What are the dimensions of your tank? What color of bulbs are you using? What ballast are you using? This will help a lot with determining things.

 

[StephNewman]

12 inches off water, 250w 14k Phoenix, current USA 2 bulb metal halide fixture with moonlights and two retrofit blue plus t5. Tank is 120 48 x 24 x 24. The bulbs are putting out 1200 par by meter when you have meter pretty close but by the time you go 12 inches to the water it is in 300s then once you go under the water it drops into the 200s and a few inches in the water down into the 150s or lower. When placing meter on bottom of tank in middle it is in 70-80 range

 

[u4ick]

Wow, that's pretty low readings for 250's. Is it a new meter?
Those reflectors aren't helping much.
I've found "fixture" type MH are a waste when compared to what a good reflector can do.

Had this same issue with the Coralife Aqualight Pro units. Have a pile of them collecting dust in the garage.

 

[Nanook]

Get some Lumen Bright, Lumenarc or Lumen Max reflectors. Hopefully you are running the M80 ballast with the Phoenix 250 watt bulbs as well(spec ballast).

 

[Schplitter]

WOW that's low.

I have one 250W 20K with M80 ballast in a Lumen Max mini reflector over a 48X18X31" tank and I get reading crazy readings out of the water. In the water I got 750-100 at the bottom. I suspect your meter is off or your running a bad combination of ballast,bulb and reflector.

Here is the thing. For the type of coral you are growing I would say leave it alone. It's clearly working. If you decide to make adjustments make sure you acclimate your coral.

Just my .02,

BK

P.S.: There is an app you can download to your phone that does a pretty good job of reading par. I had an old phone that I vacuum sealed in a freezer bag. Kind of ghetto but it did the job. I did this to compared it to a par meter and it worked pretty well.

 

[Reeferhead]

The club's PAR meter you used is about 3 years old so its about due for a recal. That said, we recalibrated the older club meter at about 5 years and it wasn't off by that much maybe 15%. I agree with everyone else, you have very poor reflectors. If you want to stick with MHs get better ones. Lowering the fixture will help increase the PAR numbers but obviously it will decrease the spread, always a tradeoff.

 

[cobra9]

I have good reflectors you can buy. I was getting 130 - 290 par 20" deep in my tank.

 

[hampmp]

I have a spare Hamilton reflector sitting in my garage.

 

[frogspawn74]

Just another thought. How clean is your water. Tinted water can severely reduce par. Run ozone or carbon?

 

[frogspawn74]

And one day I need to borrow that par meter!!!!

 

[StephNewman]

I will be bringing par meter to frag swap to turn it in. The ballast are the current ballast that came with the fixture will have to check to see if it says m80 or something on it. Cobra how close did you have your lights when you got those numbers and what type of reflectors are they and price? Schiplitter how far off water is your lights? I can't really compromise distance as it is a 24" wide tank soon don't want to get even less light to the back and front of tank by lower light.

 

[cobra9]

My reflectors were 18inches off the water. The reflector is lumenmax elite. However I have 1 on hold already for someone else.

 

[frankabagnale]

P.S.: There is an app you can download to your phone that does a pretty good job of reading par. I had an old phone that I vacuum sealed in a freezer bag. Kind of ghetto but it did the job. I did this to compared it to a par meter and it worked pretty well.

What's the App called?