Disappointed in T5 par readings

[Miami Reef]

Running a total of 16 T5 bulbs on my 260 gallon.

Took a par reading and was disappointed in my readings. I have about 350 par on average. I genuinely expected much much higher readings. I do get some light spill so I will need to lower the fixture more. Just kind of regretting and feeling like I spent more money for less par.

 

[Sean Clark]

I actually think that is pretty good for t5 only spread over that tank. What did you have over the old tank? Sorry I don't recall.

 

[rtparty]

350 PAR is plenty for anything and too much for a lot of LPS.

Do you have the bulbs all oriented properly? Are the fans running the proper speed? Are the fans controlled by the light? Do you have any ATI actinic bulbs by chance? How old are all the bulbs? How high are they over the water? They need to be 8" or so off the water.

 

[Big E]

Don't overthink it...........we've already talked about this.

Old school T5 only---

Krzysztof Tryc - reef tank 09-2016

Colombo natural reef salt, reactor with biopellets from DVH (the Netherlands), bacteria Biogro 123 marine from DVH, Colombo colour 1,2,3 (microelements), ATI powermodule 10 x 80W.

aquatic-videos.com

 

[Perry]

Don't overthink it...........we've already talked about this.

Old school T5 only---

Krzysztof Tryc - reef tank 09-2016

Colombo natural reef salt, reactor with biopellets from DVH (the Netherlands), bacteria Biogro 123 marine from DVH, Colombo colour 1,2,3 (microelements), ATI powermodule 10 x 80W.

aquatic-videos.com

Man Krzystof tank was an all time favorite!

 

[spsick]

I’m getting a max of 400 par and average closer to 200 with 6x54 over my 75g and have great growth on everything. You may have less par than led but you have more a coverage. Like a nice warm blanket that wraps up every coral nice and cozy.

 

[Bpb]

Agreed. Those par numbers are fine. You can lower the fixtures some to increase it marginally but I think it’s just a situation of t5 light being so scattered and diffused. It’s not as concentrated of a downward beam. While the meter may not be reading as high, a branching coral will be better illuminated overall. Kind of a situation of the colony receiving lower intensity over more of its biomass, vs higher intensity over less of its biomass. It’ll average out. Don’t sweat it. This is one instance where absolute readings aren’t as important and can be misleading on effectiveness and application

 

[Miami Reef]

@Big E

Small update that I forgot to post back in this thread

I am using this bulb combo in each 8 bulb unit:

Front to back:

Blue Plus
Coral Plus
Actinic
Blue plus
Coral Plus
Actinic
Blue plus
Coral plus

Took a par reading. The middle of the tank reads 400-420 par. Fixtures are about 6-8 inches from surface.

Thank you Ed! I really appreciate your help. That tank you posted is so beautiful. I really like T5 technology.

Corals are doing very well.