this is my first post here, but i have been reading allot about plants and aquariums here for several months. so i thought i would give back a little by providing you with some information i have gathered.
just here in the past 2 months i have started playing with a planted tank and me being who i am, i began right away modifying and losing the stock lid and lighting all together
. during this process I have tested and analysed many leds and thought I would share my findings.
out of all the leds i have tested there is one that has caused explosive plant growth. its a 3w 4000k Avago moonstone led with a built in diffused lens.
i am only driving it at 450MA on the tank currently but it is capable of 700MA and with a large heat sink I have pushed it to 1 amp without it going blue.
during this process i have discovered the K or Kelvin temperature of an led doesn't make a hill of beans for plants lol the one thing that stands out with this particular led it has a huge spike in the 580nm to 630nm range also a slower drop in the 630nm to 680nm range than others i have tested.
here the readings from the large spectrocolorimeter I have access to
so for all your DIY aquarium lighting, don't payay as much attention to the Kelven of an led, its basically an average system of colors. instead find the data sheet for it and look for specific frequency spikes. this varies greatly between manufacturers and models. also i am sure totally different frequency's are needed for chorals and such.
here is my Diy lid. its on an Aqueon 15g column. and with all lighting on its is total 96 watts
but i never have more that 2 of 4 sections on at one time. i rotate them throughout the day on timers to simulate the sun passing.
Edit( just found most of what I said in the LED Lighting Compendium sticky.....) i still recommend this led for FW plants