First, let me say I’ve read a TON of threads here on DIY LED stuff, but I haven’t found anything matching my goals.
I have a 48x18x18 tank (64gal) currently running a Fluval 3.0, which I have decided to supplement with a pair of DIY LED pendants. Depending on how I like the pendants, they may totally replace the Fluval. Growth is great with the Fluval, but I’d like a bit more intensity at the substrate to get stuff to grow bushier. I’m also looking for better coverage; my Fluval leaves a big dark spot at the surface. My primary goal is to make the plants/tank look nicer. I find the Fluval doesn’t have enough punch in the red channel for my taste, so I’d specifically like more power there. I’m also looking for a bit more shimmer/caustics.
I want the setup to be per-channel dimmable/programmable (likely via Arduino), but I should be able to figure that out on my own. Seems like there's a lot of good info here that I just haven't explored yet.
I played around with Spectra and worked out a bunch of overcomplicated setups before deciding to simplify by using high-CRI whites (which are sadly not programmed into Spectra). Particularly, I came across the Bridgelux Vesta Tunable Gen 2, which is a single COB with cool and warm white channels. The lower CRI offerings are not terribly remarkable, but the 95-CRI “Thrive” version seems unparalleled.
This option is appealing to me because of its simplicity and small package size (which I imagine leads to nice color mixing). I plan to get the BXRV-TR-2765S-20A0-A-23-S2, which can put out about 1700 lumens between both channels. My Fluval produces 4250 lumens, so a pair of the Vesta chips would fall a bit short of being able to totally replace it. Maybe I’d add a third pendant if I decided to replace rather than supplement it.
Anyway, my question is what to round out the tunable chip with. I’m sure the chip on its own would be plenty of light, look nice, grow plants well, etc., but I want to be able to fine-tune color more than cool/warm. The Vesta chip is a 20mm square, so a nice arrangement would be one 2cm star board on each side. I’m drawn to the triple chip star like
these (same site has two others that are a bit more expensive). I’m thinking violet, blue (specifically 460nm to fill the dip in the 6500K), deep red, and far red. Or perhaps I should trade the far red for blue or a royal blue – I’m wary of a red-heavy build causing leggy plant growth, and most LED systems have a pretty sharp royal blue spike I’ll be lacking.
I’m also curious if you have any recommendations regarding optics and/or reducing glare, etc. One big pet peeve is glare from lighting. It’s a rimless tank, and I sit with my eyes just at the water level, so glare will be super hard to avoid. I’ve thought about tilting the pendants, creating a shroud around their perimeter, etc., but I haven’t landed on a good solution. The star board chips are ~165° viewing angle, so I’m certain I’d need some optics to avoid atrocious glare. However, the widest optic I could find was
this one at 72° viewing angle. I’m not certain how well that would pair with the 120° of the Vesta chip.
Lastly, color mixing is a concern. The colored chips would be over an inch apart, and I don’t have the experience to say whether that would cause noticeable “disco” effect.
Any thoughts on 1) supplementary chip choices, 2) optics, and 3) color mixing?
blueacro.com
