Hey all,
As many of you know, I've had my full Acropora tank running for about 9 months now with great success. About 2 weeks ago, out of the blue, I started having issues with PE, RTN, etc. I'll get into that another time and what steps I've taken.
I have the 36 inch Reef Brite MH 250w that has two 250w DE bulbs and using Reef Brite 250w electronic ballasts. I was supplementing with 2, 36 inch illumagic Blaze leds. During my issues, I turned off the halides and ran only LEDs, adjusted for PAR to be the same as with halides.
Tonight, I was messing around with my Reef Brite MH and out two new Hamilton 20k bulbs in. I turned off the LEDs and lowered the MH fixture to adjust for PAR. I was first surprised and then very curious.
Here are the needed information. MH fixture mounting height was 7 inches (glass panes) from the water surface. Acropora were positioned about 12 inches below the water surface. Water is 20 inches deep total.
New bulbs that had only been on about 10 minutes were reading 460 PAR. I was surprised by that with 20k bulbs. I let the bulbs warmup for about 30 minutes and the brightness visually dropped. Same height after 30 minutes, PAR was reading 284.
That seems very low to me. I would think with the fixture dropped that low to the water that I would be getting much higher PAR. Of course the reading was taken 12 inches under the water. Sound right to you?
Pics below, disregard messy tank, still cleaning up after some issues.
As many of you know, I've had my full Acropora tank running for about 9 months now with great success. About 2 weeks ago, out of the blue, I started having issues with PE, RTN, etc. I'll get into that another time and what steps I've taken.
I have the 36 inch Reef Brite MH 250w that has two 250w DE bulbs and using Reef Brite 250w electronic ballasts. I was supplementing with 2, 36 inch illumagic Blaze leds. During my issues, I turned off the halides and ran only LEDs, adjusted for PAR to be the same as with halides.
Tonight, I was messing around with my Reef Brite MH and out two new Hamilton 20k bulbs in. I turned off the LEDs and lowered the MH fixture to adjust for PAR. I was first surprised and then very curious.
Here are the needed information. MH fixture mounting height was 7 inches (glass panes) from the water surface. Acropora were positioned about 12 inches below the water surface. Water is 20 inches deep total.
New bulbs that had only been on about 10 minutes were reading 460 PAR. I was surprised by that with 20k bulbs. I let the bulbs warmup for about 30 minutes and the brightness visually dropped. Same height after 30 minutes, PAR was reading 284.
That seems very low to me. I would think with the fixture dropped that low to the water that I would be getting much higher PAR. Of course the reading was taken 12 inches under the water. Sound right to you?
Pics below, disregard messy tank, still cleaning up after some issues.