# led lighting for 90 gallon



## coffeetwitch (Jun 21, 2016)

90 gallon tank, 48x18x24(top to bottom) standard 90 gallon tank. i just placed an order for a 48" finnex ray2 (duel 7000k) and a 48" finnex monster ray. i am not opposed to co2. i have googled and searched this forum. all the threads i find get responses, but the replies often stray way from the topic and end up saying 1 18" fixture on a 29 gallon tank has plenty of par. this doesnt help me with my specific situation.

looking for lighting that will allow me to expand to higher demanding plants if i want to and if i have to go co2 i can. 

tank is a dicsus community. brightwell FlorinVolcanit Plant Substrate, currently have two swords (would like to add a marble queen), a couple java ferns, some temples, 1 water sprite, and lastly, dwarf sag but thinking about replacing it with Staurogyne repens. im really wanting full ground cover, and eventually enough of something to hide the back wall of the aquarium. currently adding flurish and excel every at every water change. seachem root tabs under most of whats planted. my current light is my old saltwater led with just the 10,000k whites on a 213watt fixture.

primary question is, will the two lights i just ordered do the job or should i add another ray2? 

thanks


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## jeffkrol (Jun 5, 2013)

coffeetwitch said:


> 90 gallon tank, 48x18x24(top to bottom) standard 90 gallon tank. i just placed an order for a 48" finnex ray2 (duel 7000k) and a 48" finnex monster ray. i am not opposed to co2. i have googled and searched this forum. all the threads i find get responses, but the replies often stray way from the topic and end up saying 1 18" fixture on a 29 gallon tank has plenty of par. this doesnt help me with my specific situation.
> 
> looking for lighting that will allow me to expand to higher demanding plants if i want to and if i have to go co2 i can.
> 
> ...


PAR for the RayII plus monster ray at 24" is like 62
(50 plus 12)
Adequate for most things but not really "spectacular"..
If your trying to match your old fixture ( I assume 50/50 blue white and your just running the white channel??? and 90 degree lenses)
what you picked won't cut the gross output of it ..

Even at 1/2 output you are probably putting out 100PAR at 24"..guessing at a normal height.
Oh and the width makes it a little more problematic w/ the small emitter/close to the top lights,

I would think about the second RayII a bit..


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## coffeetwitch (Jun 21, 2016)

so if i buy another finnex ray2, bringing the total to two finnex ray2's and one monster ray, will that give me a solid medium range of lighting? still no need to add a co2 system?

thank you for such a quick reply btw


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## jeffkrol (Jun 5, 2013)

coffeetwitch said:


> so if i buy another finnex ray2, bringing the total to two finnex ray2's and one monster ray, will that give me a solid medium range of lighting? still no need to add a co2 system?
> 
> thank you for such a quick reply btw


62 is solid medium lighting (more like high) and would already benefit from CO2.

Part of the problem is back/front coverage..not up down..
but:
http://www.plantedtank.net/forums/10-lighting/943114-low-med-high-par-values.html
Check this..


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## coffeetwitch (Jun 21, 2016)

Understood. Adding another ray2 is to help even dispersment front to back, not entirely to add total par at substraight. Two ray2 with the monster ray in between them will give me medium to low-high lighting. Because of this, co2 would be beifitail.


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## Freemananana (Jan 2, 2015)

The 24/7 at 21" is enough to grow algae with fast growing plants and no CO2. The Ray2 will be an algae machine. I would personally just suspend the light above the tank a couple inches to get a more uniform spread. 18" isn't that wide and can definitely be done with a single fixture IMO. Adding two lights would be an ungodly amount of par and you'd have to find a way to dim them to something like 30% because the overlap between the lights would be extreme. That or add pressurized CO2.


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## jeffkrol (Jun 5, 2013)

coffeetwitch said:


> Understood. Adding another ray2 is to help even dispersment front to back, not entirely to add total par at substraight. Two ray2 with the monster ray in between them will give me medium to low-high lighting. Because of this, co2 would be beifitail.


Well, no, and as alluded to above.. the 2 will add quite a bit at the substrate so 100-ish PAR is possible.

so really the 2 choices are probably raise the RAYII giving probably 40-ish PAR or adding another RayII and CO2 or a way to cut the light a bit. Like seperate timers or other more "fancy" ways..Like hacking in a dimmer..
The second Ray II is certainly not a necessity..
Adding a finnex stingray or "equiv" is also another option for boosting spread w/ a lower PAR impact.
Depends what you have in mind.. i.e what is the more important needs..


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## coffeetwitch (Jun 21, 2016)

thank you both for the tips and info for my set up


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