Is 270 umol/m2s good numbers?

could someone help me understand what this means?? 270 umol/m2s. is this a good number? thanks

Generally accepted “good” numbers are:

Seedlings: 300
Veg: 600
Flowering: 800


@dbrn32 could you help this grower out?

I’m assuming you mean 2.7 µmols/j ?

If so, yes 2.7 is pretty good. Some lights are approaching 3 µmols/j, but it wasnt that long ago where 2 µmols/j was unheard of.

What lights are you looking at?

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no… the manufacturer posted that this light makes 270 umol/m2s at 18". yintatech 1500 watt/279 true watt.

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Ah, Now I see.

Well, my opinion on amazon blurples is that one can find much better lights.

With 279w at the wall, that light will effectively flower about 5.6 sq ft. Basically 2.3’x2.3’. Enough for 1 med sized plant. It’ll do the job, just not with high efficacy.

For example, this light will flower almost the same size area, but only draw half the wattage, and with a better spectrum.


does 270 umol mean my light is producing 270 par at 18"?


It means that it probably does directly underneath the lamp in an area about the size of half dollar. If you start moving sensor further away from center of light those numbers will drop. The smaller the fixture the faster they will drop.