Well, I took a break from plants for a few years while I was heavily into reef tanks, but Im back.
I am planning on building a new LED array using recycled parts from my 265 Gallon reef, squished down into a rimless 48x18x18 tank and was hoping for some practical feedback. Keep in mind I already have these LED's but am simply mounting them on a new fixture, but am open to the idea of changing out strings of them over time.
LED's will be mounted to a pair of 6" x 20" tapped heatsinks from RapidLED,
and the heatsinks will be hidden in a suspended wooden frame (to match the stand) from the ceiling. Each heatsink holds 36 LED's in four rows of nine. Pattern will be 2 x White, 1 x Blue staggered by one LED every row.
W W B W W B W W B
W B W W B W W B W
B W W B W W B W W
W W B W W B W W B
In this arrangement when the two heatsinks are placed next to each other the pattern continues for ever coverage.
I hope to hang the fixture about 12" over the tank, which will give me about 26" between the emitters and the substrate, and will be using 60 degree optics.
The idea is to run 48 Cree XP-G Cool Whites and 24 Cree XP-E Royal Blues (simply to balance out the heavy yellow appearance of the XPG's and will probably be running very, very low mA).
I'll be driving all 72 LED's using 6 x Meanwell ELN-60-48D's (I already own them) and my profilux III will control the dimming (already have the ballast control boards for this as well).
With this many LED's I will be actively cooling the heatsinks with speed controlled fans (profilux will speed the fans up as intensity increases on the LED's).
I have built 7 LED fixtures for saltwater aquariums so I'm pretty comfortable with the assembly end of things, but the last time I was doing planted aquaria I was still using power compact bulbs or T5's.
I would like to achieve par values at 100 (or a touch more) at the substrate which I think I should be able to do at around 750-900mA out of the driver based on the LED spacing (keep in mind it will be actively cooled). I'll be dosing CO2 heavily, already have all my CO2 gear prepped and will be using a Profilux 4 Pump Dosing pump to dose my ferts automatically every day.
I know that this is probably too blue, but I think I am more inclined to swap out 24 of the Cool whites for Neutral or warm whites while maintaining the blues to balance the colours out (just at a lower power).
I haven't been able to find too many build threads for 18" or wider tanks using LED's so I"m a bit concerned about coverage (it has been several years since I have been active on the forum). I am hoping that with this dense pattern I will be able to cover the front and back of the aquarium pretty evenly (I can raise the fixture and turn up the power if need be, the drivers for my XP-Gs are dialled in to max out at 1100mA at 100%).
I guess I don't have specific questions exactly, but really would love to hear from other LED Diy folks
Sorry if this turned into a ramble, Ive been churning through ideas like a madman for a couple of weeks and this is what Ive managed to come up with so far. Once the details are hammered out I'll start a build thread.