desertranger
Member
good light for a 40G breeder frag tank ? want to grow a little of everything if possible
good light for a 40G breeder frag tank ?
- Thread starter desertranger
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sirrealism
Well-Known Member
There are a lot of choices. You looking to go MH, T5, or LEDs? of a combo. A 150 MH will do just fine and you can grow anything. T5 I would go with a 4-6 bulb 30" depending on manufacture. Leds this is one that is tough. I have a 40b and will say I never had better luck with it as when I ran 2 AI nanos on it.
desertranger
Member
I think I am going to go with reef breeder photon 24 or 32
sirrealism
Well-Known Member
I think the 24 would do great. The 32 is a bit larger then the tank since the tank is 30". I do know several people who use these and love them so I would think its a good choice. With the light being 24" that works out to just 3" on each side which wont be a problem at all.
desertranger
Member
The tank is actually 36*18*18. But I think with the spread the 24 will be ok.
sirrealism
Well-Known Member
Opps ya your right. But yes I think the 24 would cover it fine. I had a d120 over it pretty high up 18+" and it covered well so I would think the 24 should do well
No it won't be "OK". LEDs tend to direct their light straight down. A 24" fixture will leave you about 6" of dim tank on each end. Go with the 32" fixture, since your tank is 36" long. You will not regret it, especially if your talking about growing SPS corals. Yea, I know the 32" fixture is a lot more expensive.
NanaReefer
Member
Don't optics help with the spread?
reefer gladness
Well-Known Member
Yes, wider optics increase the spread at the expense of the light being less concentrated. Conversely more narrow optics focus the available light into a tighter area.
Light from LED's is directional but doesn't only go straight down. Without optics most LED's have a 120 degree beam angle with the greatest intensity of light at the center and getting progressively dimmer as you go out toward the edges. If you were to add 90 degree optics for example the beam angle is reduced by approximately 25% from 120 degrees and the amount of light concentrated in that area increases by a similar factor (though optics are not perfect and there is some loss).
Mounting height has a similar effect whereby mounting the light higher increases spread and reduces light and the opposite when mounted lower.
A good visual representation of this can be seen with a flashlight shown against a wall. The closer you get to the wall the smaller the lighted area and more light directed there. If you have a Maglite or similar flashlight with an adjustable lens you can stand in the same place and adjust the lens to observe the effect of having a wider beam angle or more narrow.
FWIW, both mounting height and optics need to be considered when picking out your LED fixture. The OP could use the 24" as originally planned but it would need to be mounted pretty high to get decent coverage over the edges of the tank. So high that I expect the light will be bleeding over the front and back of the tank and would be a distraction in the room. Personally I would go with the 32" so the mounting height can be kept reasonable.
desertranger
Member
Thanks all. I am planning on going with the 32" fixture
sethsolomon
New Member
+1 Halides will give you the best growth but are a bit more expensive to run.
IMO T5's are your best bang for the buck. you can get 4-8 bulb t5ho fixtures for cheap on ebay.