Light meter? Updated with measurements

I imagine it can help in determining if the bulb has faded, but I don’t think it can measure the individual spectrums. If I understand the AG literature correctly, the bulbs still appear quite bright at 6 months but no longer have enough of one or more or the spectrums that the plants need.  In fact I bought adapters to use the 6 month+ old bulbs in closets and such because they’re still perfectly bright for such use but not for growing things.  Except lettuce.

What I’ve done in the past is plug in a brand new bulb next to the suspected older ones because if the old one is old enough you can kind of see the difference. Just don’t look at them for long!  I now also write the start date on my new bulbs. Because there’s no way I’m going to remember so many of them!

Lettuce does ok. It just grows slower and not as robust, maybe a bit spindly. But you can still grow it and enjoy and consume it, unlike, say, a pepper plant which really needs newer bulbs. In an ideal world you could plant all lettuce gardens and see which ones grow slowest, and toss those bulbs. (Hah). I think Choi might be ok too, just smaller. 

Very interesting range of light!  I’m intrigued that the Harvests are so much higher than the 7 LED.

Very possibly. (Not that I have one iota of knowledge on the subject, lol, but it sounds good to me!)

Don, what difference did you notice? That the Harvest is brighter than the Ultra?

The first set of measurements ( aerogardenaddicts.com/post/12353 ) were taken at approximately the same distance from the hood.
The second set (in which I show a photo aerogardenaddicts.com/post/14546 ) were taken by laying the sensor on the deck, so the Harvest was considerably closer to the lights.