PAR too high?

[Banana Man]

I tested my PAR and Lux for the first time today with my Seneye Reef. I have a shallow tank and am running 6 x 80W T5's. I am only running them at 80% power. The results were:

PAR:
Bottom: 470
Middle: 600
Top: 815 (1 inch below water level)

Lux:
Botom: 17,000
Middle: 22,000
Top: 31,000

I have done a bit of Googling and from what i have seen so far my readings are a bit too high. Should i lower the power output a little bit more or should this be ok?

Thanks

 

[Sakura2282]

I thought the bottom reading should be 150 - 200 PAR, but that's for a deeper tank. If you have a shallow tank maybe you don't need your T5's running at 80%. What kind of corals do you have? If your tank is full of SPS corals then you are probably OK but, I'm not a PAR expert. Are your corals doing well? What's the photoperiod exposure? Just curious.

 

[reeffreak]

PAR is too high for most LPS and soft corals.I'm not an SPS keeper but that might be good for those.

What corals do you have?Are any of them bleaching?

 

[Banana Man]

I have a mix of both LPS and SPS. I have the LPS at the bottom of the tank. Everything seems to be doing well except for my Montipora Capricornis which has small bleaching going on the last week. I had put my lights up to 100% a week before that so im hoping that is the cause. I put 2 Blue on at 12:00. Another 2 Blue and 2 White and 13:00 all gradually up to 50%. At 14:00 i bring everything up to 80%. At 18:00 i bring everything down to 50%. Then the reverse of the start with everything completely off at 20:00.

 

[Sakura2282]

How far from the tank are the lights hung? It could be that the light is too strong and that's why your corals are bleaching, maybe if you hang them a little higher it could help to stop it.

 

[BL1]

I've got a hard time believing those PAR results only be a use you're posting higher readings then from 250w MH which penetrate better.

A while back CcCapt posted these from his meter.

250w XM 10k 1" below 1060, 12" 520, 24" 340

With that being said, a T5 fixture will never mimic the intensity of the sun.

 

[reeffreak]

I believe those PAR readings if the OP is using the ATI Powermodule.It sounds like from their description.I do like to say 470 is a lot of PAR for LPS corals.I'm running 100-200 PAR at the sand bed..which is considered moderate.

 

[Banana Man]

Hmmm, my tank is only 17" high and the lights are fairly low over the water. Maybe i'll have to reduce the intensity dow to 60-70%. And there was me thinking more light was always better!

It probably explains my green hair algae problem as well. I have Nitrates at 0 and Phosphates at 0.06 and yet i keep on getting large amounts of Green Hair Algae on the upper rocks.

 

[reeffreak]

More light isn't always better.I'm only running my LEDs at 40-60%.I was basically cooking my zoas at one time.