help in DIY led light for a DIY 28 galone tank

[Gamezawy]

hi there

i have made a tank just like 60P ADA tank well it will be for shrimps so i am keeping only low light plants so there will be no co2

as for hoppy's PAR Calculator i found to have about 30 par in my tank i will be needing 6 CREE XML LEDs

i will be running them by 2 Am with 60 degree lens and they will be 28' above the substrate 2 rows and led spacing will be 5.28'

so do you see it is good and it will give me what i want for low tech tank

this tank's aquascape is tree and some rocks i will be using anubias nana on that tree

this pic for the leds above the tank

[Gamezawy]

Any one would help and give me suggestions ?

[Hoppy]

My only suggestion is to be sure to use a LED driver that can be dimmed. I don't know a good way to design such a light to get exactly what you want, so the best idea is to design for more light than you want, with the ability to dim it down to get what you really want.

[Gamezawy]

thanks hoppy but one last thing all i wanted to ask , is 6x CREE XML leds with 60 degree lens are enough for that tank or i will be needing more because when i order leds it come after 2 months :S ?

[Hoppy]

I think I would use 40 degree optics, then you could get that much PAR with less than 700 mA LED current, so the heatsink will not be at all critical. Here is what the calculator shows for that:


The problem with the 60 degree optics is that you would need over 1.5 amps of LED current for that PAR. That means the heatsink would need to be very good to avoid overheating the LEDs and shortening their life.