mixing spectrums is actually a really good thing . Any qb board will already have a wide spectrum .
And to make things more clear . A high pressure sodium grower that has will say 4000 watts will greatly benefit from having a 250 watt metal halide in the middle of the grow . Hps 2700 k . Mh about 6500 average . .
Always mix spectrums there are many benefits . Look at the sun . Has everything .
edited . No need to spend thousands o these boards . Look at vipar spectrum or a cheap ebay there all the same . I used a cheap 30 dollar light posted pics of the plant wile it was growing over on a different website . I pulled 6 ounces from a 30 dollar light one plant. vs a samsun board . Same yield .
Yep, this works well - back in the day we used to "light cycle" between HPS and MH to turn on and off with a few hours of overlap, the HPS would cycle on/off 3 hrs morning and 3 hrs evening, MH's would cycle on /off mid morning to late afternoon - we were trying to emulate morning/evening reds - and midday sun (uvb) - right on!
Hear Hear!! HPS and MH at the same time is the best. They love it. My veg room was suddenly empty so i put the metal halide in the bloom room that had 2 1000 watt hps lamps going and that was the best grow i ever had the plants just turned into monsters. I got these blurples some one gave me i might stick them in the flower room. I dont have an MH right now. When it comes to light offer the plant the fullest spectrum you can and the plant can decide what it wants. When you see these plants outside and there just sucking up the sun like you would be burnt to a crisp if stood in the sun that long..and these plants just love it. They run on radiation.