Jim, excellent questions, thanks. I actually leave the Phals at the
periphery of a 250W HID in which I alternate between MH and HPS
depending on the season. But even at 5 feet off center, it's still
pretty bright, maybe too bright. I grow in CHC's and add Epsom salts
once a month, though that may be more myth than anything. I'll stick
with Dyna Grow. I've never been certain about light duration, and try
cutting back to 12 hours in winter for a few months, and up to 14 hours
in summer, but good to hear that may not be necessary. These plants
were left outside this summer and got too much rain, I fear. I think I
did get some root loss and that could account as well for a shrinking
harvest. Thanks for all the useful observations and info.

Charles