Disappointing MH PAR numbers?

Bronx19 · Mar 6, 2019

I get 150+ at the bottom of 18" of water, mounted 8" above surface, from 150w Ushio 10k.

alton · Mar 7, 2019

Before I was able to borrow a Par meter I used a foot candle meter. If you can find coralvue luminbright pendant you be amazed how well they reflect the light into your tank.

https://www.coralvue.com/lumen-bright-mini-metal-halide-reflector

sghera64 · Mar 7, 2019

Knapp870 said:
Using 3 250 watt halides and a actinic sbar knock off on my 220 gal. Par is extremely lower than I anticipated. Do I need better reflectors or time to rethink lighting? I ditched led as I didn't feel they were reaching and had the spread I needed (only 3 over this tank) and I wanted to try old school. Overall everything is healthy but I'm focused on growth and color and worry I'm missing... 250ish par at water line!? 2 radiums and 1 Hamilton 10k

FWIW: 5” below the surface I’m getting 126 and 146 PAR. I have a 250W Radium with a 250W Luxcore Ballast on HQI setting housed in a Hamilton Cayman Sun reflector and the bulb is 18” off the surface. The bulb just hit about 100 hrs when I measured it. I’m using the Apogee 510 sensor on my laptop. The bulb I changed from was an 18mo. Old Radium 250W and it was reading 126 and 146 at 5” below surface 3 weeks ago just before the switch-out. So, my numbers are close to the OP’s numbers.

Acroporaaddict · Mar 7, 2019

Radium on M80 ballast, 315w 3a

Surface 530
2" 470
4" 430
6" 380
8" 350
10" 330

Acroporaaddict · Mar 7, 2019

sghera64 said:
FWIW: 5” below the surface I’m getting 126 and 146 PAR. I have a 250W Radium with a 250W Luxcore Ballast on HQI setting housed in a Hamilton Cayman Sun reflector and the bulb is 18” off the surface. The bulb just hit about 100 hrs when I measured it. I’m using the Apogee 510 sensor on my laptop. The bulb I changed from was an 18mo. Old Radium 250W and it was reading 126 and 146 at 5” below surface 3 weeks ago just before the switch-out. So, my numbers are close to the OP’s numbers.

Hmm. I'm getting significantly more par with my luxcore ballast on a roughly 100hr old bulb.

Knapp870 · Mar 7, 2019

Sooo much conflicting info. Lol. Some are getting 250-300...some are getting 530 and some get 1100+ lol

sghera64 · Mar 7, 2019

Knapp870 said:
Sooo much conflicting info. Lol. Some are getting 250-300...some are getting 530 and some get 1100+ lol

What light meter r u using?

Knapp870 · Mar 7, 2019

sghera64 said:
What light meter r u using?

Apogee mq-210

sghera64 · Mar 7, 2019

Knapp870 said:
Apogee mq-210

I know from BRS Investigates and from an e-mail I got from Apogee that the serial number on my SQ-520 puts it in the range of sensors that are under sensing/reporting the upper blue and UV. Maybe that is part of my difference from what is expected. Know that my Apogee is just the probe on a USB cable. Apogee did send me new software to use with it, but it seems to give me about the same values as the prior software version. They reported that the readings are under reporting by up to 20%, but only in the 400-420 range. So that does not explain things here.

I do know corals grow well and full beneath this lamp, but that does not say much since corals will adapt to what you give them so long as they get over a certain minimum (like more that 70-100 PAR)

Bpb · Mar 7, 2019

Just performed some par readings on some halide gear I just acquired
Apogee qm510
Lumen bright mini
Hamilton 14k (3 months old)
Hamilton m58 ballast

Base of reflector to bucket: 11”
Base of reflector to water level: 14”

Par in air at 14”: 1250
Par under water at roughly 14”: 1050
Par at bottom of bucket:

So at 14” of air and under 11” of water a par of 800+ to me is not just impressive, but seems borderline unusable. I was planning to install these over the tank this weekend but that is 2.5x the par I currently enjoy at a similar distance. I need to maybe order some 20k bulbs and consider putting some glass shields over the water maybe? I don’t know how to acclimate that much of a jump. Changing over from an 8x54 ati sunpower to 2x250 watt lumen bright mini. I don’t love the 20k look, actually prefer 10-12k without supplements. But I may need to learn to love them to get into an acceptable par range. Thoughts?

Those of you who use actinic LEDs with your halides, do you run them all together? Or only turn on your LEDs before and after?

Knapp870 · Mar 7, 2019

Bpb said:
Just performed some par readings on some halide gear I just acquired
Apogee qm510
Lumen bright mini
Hamilton 14k (3 months old)
Hamilton m58 ballast

Base of reflector to bucket: 11”
Base of reflector to water level: 14”

Par in air at 14”: 1250
Par under water at roughly 14”: 1050
Par at bottom of bucket:

So at 14” of air and under 11” of water a par of 800+ to me is not just impressive, but seems borderline unusable. I was planning to install these over the tank this weekend but that is 2.5x the par I currently enjoy at a similar distance. I need to maybe order some 20k bulbs and consider putting some glass shields over the water maybe? I don’t know how to acclimate that much of a jump. Changing over from an 8x54 ati sunpower to 2x250 watt lumen bright mini. I don’t love the 20k look, actually prefer 10-12k without supplements. But I may need to learn to love them to get into an acceptable par range. Thoughts?

Those of you who use actinic LEDs with your halides, do you run them all together? Or only turn on your LEDs before and after?

That's crazy. I run mine before and during and a little after. Essentially actinic led bar for 11 hrs a day and halides are 6 hrs

sghera64 · Mar 7, 2019

Bpb said:
Just performed some par readings on some halide gear I just acquired
Apogee qm510
Lumen bright mini
Hamilton 14k (3 months old)
Hamilton m58 ballast

Base of reflector to bucket: 11”
Base of reflector to water level: 14”

Par in air at 14”: 1250
Par under water at roughly 14”: 1050
Par at bottom of bucket:

So at 14” of air and under 11” of water a par of 800+ to me is not just impressive, but seems borderline unusable. I was planning to install these over the tank this weekend but that is 2.5x the par I currently enjoy at a similar distance. I need to maybe order some 20k bulbs and consider putting some glass shields over the water maybe? I don’t know how to acclimate that much of a jump. Changing over from an 8x54 ati sunpower to 2x250 watt lumen bright mini. I don’t love the 20k look, actually prefer 10-12k without supplements. But I may need to learn to love them to get into an acceptable par range. Thoughts?

Those of you who use actinic LEDs with your halides, do you run them all together? Or only turn on your LEDs before and after?

Yikes! The bucket has a whole lot of unnatural reflectance going on that might be artificially boosting your measurement. Perhaps why it is so impressive. It acts almost like a parabolic reflector. Could you get a 10-20 gallon glass tank and repeat.

BRS even finds higher readings in glass tanks near the glass due to reflection.

Bpb · Mar 7, 2019

sghera64 said:
Yikes! The bucket has a whole lot of unnatural reflectance going on that might be artificially boosting your measurement. Perhaps why it is so impressive. It acts almost like a parabolic reflector. Could you get a 10-20 gallon glass tank and repeat.

BRS even finds higher readings in glass tanks near the glass due to reflection.

I literally was just about to type the exact same thing. The white bucket was giving a ton of scatter. I didn’t consider that.

MTBake · Mar 7, 2019

Bpb said:
I literally was just about to type the exact same thing. The white bucket was giving a ton of scatter. I didn’t consider that.

Most likely why the par is so high is that white bucket, kinda like a second reflector. I would go head and make the swap. If you're worried about frying coral, raise the MH a few inches above your t5s. Or reduce the photo period a bit. I doubt you'll need to though to be honest.

Bpb · Mar 7, 2019

MTBake said:
Most likely why the par is so high is that white bucket, kinda like a second reflector. I would go head and make the swap. If you're worried about frying coral, raise the MH a few inches above your t5s. Or reduce the photo period a bit. I doubt you'll need to though to be honest.

I appreciate the reassurance everyone. I’m gonna attempt the swap this weekend.