Adding LEDs into my Flourescent Fixture

[F3aReDRickA]

I've been considering adding LEDS into my current florescent fixture I use on my tank. We have a 75G tank with some soft corals and 5 fish. Currently, the 4 bulb (2 white, 2 acin) t5 fixture is working well. I've been considering getting some LEDs to add into the fixture to improve lighting in the tank mostly to make way for higher light dependent corals.

Do I need more lighting for harder to keep corals? I've been led to assume the florescent fixtures arent very impressive for a lot of corals. But with any hobby necessity and the current practices vary.

My plan was to add roughly 12-14 LEDs into the fixture. My guess was 9 white and 3 blue LEDS. To combat the extra heat I was going to add 30-40mm fans on the sides of the fixture to draw air through the unit (it currently has no fans). They are 5W diodes, but I'm guessing that is the maximum and they will run closer to a value of 2-3W.

How effective will such a low number of LEDs be in improving my overall light? I don't want to spend 200-400$ on a new fixture when mine works well and with 100$ investment I can improve it a respectable amount. I like DIY projects anyway, so thats always a plus.


Thank you for any help!

 

[BlueCoast]

I did something similar with my T-5 rig. I had 5 tubes, 3 on one channel, 2 on the other. I unhooked the 3 bulbs and retrofitted a rapidled diy kit into it.
I now run 2 T-5 whites, and 2 channels of LED's. the first channel has 9 UV led's, the second channel has 9 RB and 3 blue LED's. This gives me lots of control for dawn to dusk and tweaking my blue channels. The T-5's still provide plenty of white to match the LED's.

This is on a 40B tank.

I had no problem growing SPS with the T-5's, but wanted more control and dimming, so I put in some LED's.

I would consider splitting them up by color.

 

[F3aReDRickA]

Is the point of the UV light for full spectrum lighting for the corals? I'm not totally sure the use of UV lighting. Something to research. So I'm guessing two flourescent bulbs is enough white light then based on your experience. If I were to keep all 4 of my bulbs and add to the fixture (2 acin, 2 white) what would be the most beneficial to add?

 

[F3aReDRickA]

I'm considering just buying the 48" heatsink on rapid led and going with 4 royal blue, 4 blue, 3 UV, 1 green, 1 660nm red. Kind of modeled after their onyx fixtures. This would also be expandable as a moon light. Thoughts on the spectrum that would provide?

 

[triggreef]

I don't know about the small number your planning. I'm thinking that it will be like spot lighting because you have a 4 foot tank. Also so few leds I don't think would help get better growth or help you keep more light dependent corals then you have in the past.

Again this is just my opinion based on nothing really. I have 90 leds on my 72g. I also have 90 on my 125. Adding the extra 2 feet of length cuts the par in half per my apogee par meter. I just barely get 120 par on the sand bed in my 72.

Whatever you do though, if I had it to do over... I would buy a reef breeders light and call it a day. On a diy kit, I would go 3/4 blue leds and 1/4 white. and then throw in some reds and greens they make a ton of difference. I went 2/3 blue and 1/3 white but it is still too white for my taste. Also go half and half with royal blue and true blue. Just a better overall color.

 

[F3aReDRickA]

I would think adding like 30W of LED lighting in those spectrums would help a fair amount... That seems like a reasonable amount of light combined with my current lighting... hm.

 

[BlueCoast]

Keep in mind different colors of LED's typically have different forward voltages and power requirements. For Instance the UV led's max out at around 700ma, while the whites are good to 1500ma. This can make running all LED's on one driver problematic. I prefer a different LED driver for each color set of LED's. This gives you the ability to tweak the look to your preference.

12 LED's @ 3watts each gives you 36 watts of LED light. That would be roughly comparable to 1 T5 tube. Obviously reflectors and LED lenses can impact the comparison.

You will get better glitter lines with the LED's, but the T'5s will wash some of that out with their flat light.

There are some great LED discussions over in the DIY forum as well.

 

[F3aReDRickA]

So there isnt much point to spend 200$ to improve the light spectrum it sounds like...

 

[BlueCoast]

So there isnt much point to spend 200$ to improve the light spectrum it sounds like...

short answer... no

LED's are still working to get more homogenous spectrum. Bulbs like T-5's and MH put out a wider spectrum that covers more of the visible range. LED's tend to have lots of small spikes. As LED's advance we are seeing more diverse led colors combined to better mimic full sunlight.

I think with your T-5 setup you should have some pretty decent options at modifying the spectrum to your liking.