Par on an actual Reef.

Sdot

Valuable Member
View Badges
Joined
Aug 17, 2017
Messages
1,112
Reaction score
1,518
Location
Houston
Hey family, hope all is well during the pandemic. I was messing around with my Apogee 510 Par meter and decided to do some measurements outside in the air. It was reading near 2400 par! So i decided to fill a small bucket of water (around 10 inches deep) and collect readings underwater. The par quickly dropped from 2400 to around 1524 in just 10 inches of water, so im curious about high powered reef lighting and at what depth would the par levels in the ocean be similar to what we are getting in our home reefs.

Is it safe to say that corals are seeing similar par numbers in lets say 10-20 feet of water as they see in our aquariums at 25 inches? Anyone ever take par measurements during a diving trip...really curious.
 
First Choice

oreo5457

Valuable Member
View Badges
Joined
Sep 18, 2017
Messages
2,277
Reaction score
1,417
510 isn't accurate in air...............more correctly it's internally corrected for water:
The MQ-510 sensor has an immersion effect correction factor of 1.32.

divide your air measurement by 1.32
1818 PPFD...........not 2400


As to the rest..
 

Jaebster

Active Member
View Badges
Joined
Nov 19, 2019
Messages
453
Reaction score
984
Testing issue in water (assuming you used fresh water). Saltwater is more dense than fresh and seawater has plankton, silts, etc. When you do a water change, save the old water water (of it's clear and not discolored) and try it. I'm sure the par value will reduce than PAR in just fresh water.
 

oreo5457

Valuable Member
View Badges
Joined
Sep 18, 2017
Messages
2,277
Reaction score
1,417
Testing issue in water (assuming you used fresh water). Saltwater is more dense than fresh and seawater has plankton, silts, etc. When you do a water change, save the old water water (of it's clear and not discolored) and try it. I'm sure the par value will reduce than PAR in just fresh water.
 

cvrle1

Well-Known Member
View Badges
Joined
Sep 13, 2018
Messages
835
Reaction score
947

Didnt see that Oreo already posted this link. Oops
 
AS

alton

Valuable Member
View Badges
Joined
Feb 8, 2016
Messages
1,585
Reaction score
2,685
Location
Zuehl, Texas
If you want to simulate the sun try a 400 watt metal halide. When I used 250 watt MH Radium lamps in LuminBright Pendants I recorded Par readings of 1800 to 2000 at the water level. Which was about 9" below the fixture.
 
OP
Sdot

Sdot

Valuable Member
View Badges
Joined
Aug 17, 2017
Messages
1,112
Reaction score
1,518
Location
Houston
If you want to simulate the sun try a 400 watt metal halide. When I used 250 watt MH Radium lamps in LuminBright Pendants I recorded Par readings of 1800 to 2000 at the water level. Which was about 9" below the fixture.
My LEDs are plenty bright... i was just curious about the amount of par my tank gets would be equivalent to what depth in the ocean. At 65% im getting over 300 par at the bottom of my tank. This is with the leds mounted 14 inches above the tank. My tank is also a little more than 25 inches tall.
 

Are you currently running a reactor and media on your reef tank?

  • Yes (please tell us what in the thread)

    Votes: 92 40.5%
  • NO but I run media from time to time

    Votes: 64 28.2%
  • NO I don't use filter media

    Votes: 66 29.1%
  • Other (please explain)

    Votes: 5 2.2%

Online statistics

Members online
2,511
Guests online
6,846
Total visitors
9,357
LA
Top