# Sprouting like crazy

Sprouts are going nuts. I estimate about 100 in all. Most of them are getting close to 0.5’’. At about 1’’ I’ll thin them out. The remaining ones should have at least 2’’ of space (make a shape out of paper, or glass rim, of diameter 4’’? Could use a string, too). The algorithm that I think I’d like to try is to clear out space around the best looking one. Next, find on the perimeter that is second best and clear that one out. Continue searching on the perimeter. Can use some discretion if promising ones are near the perimeter. More pace probably OK.

I also added an aluminum foil reflector to help get a little more light in, especially to the sprouts in the the shadow of the pot (soil too low). Estimates around the internet show that the dull side (better than the shiny side) has higher reflectivity, maybe 60% at best. Mylar would be better, but this should be good enough. I’ve considered a mylar curtain behind the regular curtain.

The sheet, as is, is higher than it needs to be for now, but a full grown plant will use most of it. I really need to set aside some time to come at this problem from an illumination point of view. If I could make these things affordable, they might make some money. Passive illumination (no light required. Double the amount of sun your plant (by illuminating both sides), in a window, without needing to move it.

At night I shine a standard household LED bulb at it (60W?). Doesn’t take much away from the room, and I think with the reflector, gets at least some lighting.

Oh, and I rotate it 90 degrees every night before bed. Looking down from the top, I rotate the reflector 90 degrees counter clockwise.

# Handbook of Optical Metrology: Principles and Applications

60W lightbulb -> 45 W of flux. Light is about 1 m away. Surface area is 4 pi r^2 = 12 m^2.

So power density is 45 W / 12 m^2 = 4 W / m^2

Sun: 1000 W/ m^2

Ok, so a meter away is basically useless. Invert the equation and try again.

sqrt(45 W/ 1000 W/m^2 / 4 / pi) = 0.06 m = 6 cm, or about 2 inches. So it has to be really close.

Quarter of the power at 4 inches.