[eledill]

Tank: 55 gallon
Distance from light to substrate: 18"
Pressurized CO2 controlled by Ph relay.
PPS-Pro fert dosing schedule with CSM+B as trace.

I need a high output light for the aquarium, and I'm looking at Finnex Ray2 48" for lighting.

Do I need 1 or 2 for high light output?

(edit: I found http://www.plantedtank.net/forums/145-finnex/189944-finnex-ray-ii-fugeray-par-data.html with the PAR data, just not sure how much makes high light).

 

[jrygel]

27 PAR at the substrate (what you will have according to the linked chart) is not high light. If you are trying for a carpet of dwarf baby tears or something like that, you will probably need to spring for two. That being said, a RAY2 will give you fairly high light once you're into the middle of the column, so if you want tall high-light plants, you may be okay. That being said, two will put you into the high light range and the RAY2 isn't dimmable, so you may need to play with reduced a photoperiod of one of the lights (i.e one on for 8 hours and the other on for only four of those hours) or something to limit algae growth until you get a good amount of healthy plant mass growing.

Not too many long high light bars available anymore with Ecoxotic and BML leaving the market. You don't need two bars for coverage on a 55, so you might want to look at the Current Satellite Plus Pro or some of the Chinese imports: DSUN-Y, and Beamsworks for single light bars that will get you enough light from one fixture.

-Justin

 

[Kareen]

The Fluvals fresh/plant 2.0 LED put out high light I have two 36" on my 125 I get 66par from each

 

[sohankpatel]

I use a ray 2 on my 55 and It is growing anything I throw at it. jrygel was looking at a 16" light, the 48" gives about 70 PAR at that distance. The only plant I couldn't carpet was glosso, HC grows and so does dwarf hairgrass

 

[eledill]

I really wanted to pickup a BML light, about a week too late... I get why they did it, and I'm still not happy.

Right now, my biggest demanding plants from what I'm reading are Pearl Grass, micro swords, baby tears, Rotala Nanjenshan, and Cabomba. Sounds like I can make due with one ray2, thanks!

73-62 PAR on the specific light I'm looking at.

 

[jrygel]

I stand corrected. Yep 73 PAR is as much as you will want for almost anything. Still might want to think about ways to dim it a little bit to avoid algae issues as your plants are growing in. Maybe a screen or something similar. I have a moderately high light, high tech tank with a little bit of BBA. The BBA is usually limited enough that I'm not going to spend much time to do anything about it, but if I go over around 65 PAR, it starts to take off . . .

-Justin