I'm running jacks with no CaCl2 at the moment and the colombian girls are getting shitty brown leaf spots again at week 3-4. Third time in a row now and only in my ebb flo setup. I think it actually may be too much light believe it or not.
I am running
Cultured SOlutions in my MPB and the plants look fucking amazing. 300ppm.
No need for high ppms. Do your res changes either when the plants have drank 1/2 the water, or once a week.
I am currently running jacks in my coco at 700ppm and they look great. I am feeding DTW, for about 15-20 seconds every hour. 5 12 gallon containers are getting 35 gallons every 2-3 days. Then, they get water for 2-3 days... then they get food again... etc.. I give tea once a week. These plants are also looking superb. I will post up some pics.
I am about to switch over to regular dechlorinated tap too. The RO is too wasteful.
I actually do believe it. I've had that same problem as well with a sativa strain I bread with a Bubba. Even shot a plant training video of how remarkable the plats were hotrodding up to that point, they looked amazing., then at week 4 (you could almost set your clock to it), top largest fan leaves first mottling, flush, progression, interveinal narcrosis, flush, progressing, crispy critters, tried everything under the sun, dialed down the light. Things improved with the new plants so just kept them to the outside.
What bulb are you using? There was a guy a while back that had problems with the horitie 600 eye bulb getting black on one side, apparently those bulbs do best with a analog ballast, digital ballasts effect the wave length or something to that effect off the top of my head.. I had one as well and swear the plants didn't like it so switched it out with the
ushio hilix gro I usually use..
I run real low ppm's as well but have to due to the amount of H20 the girls are pumping, I run RO that is half recirculating, half DTW.. I run 2 resiviours one is "A" DTW and the ohter "B" recirculating that basically just receives the drain from "A". The Resevior barrels are interchangeable with my control bucket I built with backup safety switches and more efficient draining system.
I do have concerns as well for wasted H20 but am saving for the newer RO system that recaptures the waste water, and I buy half my Ro from store machines. I don't dump my rez when the plants use up a percentage of h20 (although that is one way to do it), since I run low RH, I filter and chlorinate my recaptured h20 the plants transpire in my dehui. I dump that back into the recirculating second rez. "B" which is connected to the drain side pump in my control bucket that fills from the DTW REZ "A" . This keep the ph under more control in the Recirculation rez B as well as giving the plants a couple days (or more, depending on medium) of pure DTW solution. Then after adding fresh clorinated, distilled, re filtered (zero rez filter) water from the dehuie, I top off nutes to the EC I want and switch hoses.
This gives me a lot more control, on that particular portion of my system. My buckets are aslo designed to easily be removed to independent care should they need to be.