Glad to meet someone who can understand what i want to mean. The data are computed by me, from the specs of reputable and reliable manufacturers.

A made a sheet table wich compute emission in micromols of phothons given the SPD (spectral power distribution) and lm output. This is the PPF (or PAR) data wich some agro bulbs manufactures provides, and the error margin are often below 5%.

Then, correct it by cannabis quantum yield (capacity of produce O2 from light imput). To build it, i use the photosyntetic action curve from Inada (1972), very similar to the McCree curve, and obtained like an average of 26 plants herb species. Its proved that differences with other species are little. And correct it for the cannabis spectrum absorbance (obtained from Us gov archives about MJ fields in Colombia: strain Colombian Sativa at Jul25). From that data, i obtained the PUR data. You can see details and dowload it here .

About HPS digital ballast, there are too much marketing claims. They dont increase output, but reduce power lamp mataining aprox the same ouptup and the ballast itselves lose less watts the magnetic ones. The best about HID digital ballast is they made the HPS bulbs last longer (and from that, with acrobatic maths, manufactures obtain their fantastic claims). Their problem, price, although is dropping fast, and reliability at high wattages (600w and higher).

In the other hand, fluoros digital ballast are cheap and reliable. Actually, any informed person who want to use fluoros might use them.

Im very interested on led growing, there are a thread open in http://boards.cannabis.com/showthrea...t=34819&page=7. I think its the right thread to continue talking about
knna Reviewed by knna on . Light intensity? Does equal wattage of flouros give as much light intensity as a MH or HPS? For instance, is a 100w flouro equal to a 100w MH in the vegging stage? Could you replace one with the other without affecting crops? Rating: 5