I originally stuck this in advanced, then realized it should be here... I just moved some seedlings (started in Rockwool cubes) into my ebb & grow system. They germ'd on 3/1 and by 3/13 had 2-3" of root coming out of the Rockwool. They went into the buckets on 3/15. I'm using FoxFarm GB and BB (hydro version of GB) and started out with the recommended EC/PPM of 1.0/700. I started to see a little yellowing within a couple days and did some more research. I can't find a cut and dry answer but general consensus seems to be 700ppm is way too high. For now, I dropped the nutes to 400ppm. Grow Info: pH - 5.9-6.0 Room Temp - 77f RH - 55% Res Temp - 67f Light - 1000w about 5 feet from plants for now Water - RO/DI CO2 - 1500ppm (free, thanks to my kerosene heater...its not in the room though ) Flood Cycle - 4 times/day for 15 mins (I had originally started at 8 times/day on advice from a friend, think that was too many) Tons of ventilation and all in all they are growing well. I'll try to get a pic up ASAP. Anyone with experience using FoxFarm want to chime in? I'm debating dumping the res and going with plain water for a week to flush things out, but being new to hydro I don't want to do anything until I identify the prob. Thanks! Pics below:
Anyone? I think time is running out here, not looking too well this morning. The yellowing continues to get worse. If no one has any ideas by tonight, I'm gonna dump the res and run water for a couple days. If it gets worse, it was deficiency. If it gets better, over nute'd. Just hate to experiment with the little girls...
I've recently had a similar problem with a DWC plant. I changed the res water and reblanced and nuted up slowly over two weeks to 600ppm. The problem appears to be much better on the new growth. I seriously doubt that your issue is nute burn, however I am at a loss to explain the apparent deficiency. I hope this helps a little. Oh yeah... cover those rw cubes as completely as possible with the hydroton.
Thanks ehole. It's a tough call. I think I'll do pretty much what you did. Dump the res and flush for a day or two, then VERY slowly bring nutes back up. I just hope it's not truly a deficiency as it's gonna get much worse on water only. Anyone else have ideas?
Well, they look worse today but are still growing good. I flushed out the res and filled with plain RO. Will see what happens. I was thinking I'd flush for 24 hours with the plain water, then add nutes to bring it to 100ppm. Should I flush longer? And would it be best to dump the res again or should I just keep the water and nute up REAL SLOW? This sucks!
I didn't even flush. Once I rebalanced the water I nuted up to about 100ppm. Three days later 250ppm, three days later 500 ppm, then 600ppm. Basically I used the TDS meter to determine when the plant was taking nutes, then I upped the PPM a bit. Then I maintained the 600ppm. The plant shocked a little as expected and noticeable growth growth slowed tremendously for several days. Now it's starting to recover and the new growth is a vast improvement (not perfect) over the previous state of the plant. I've got my fingers crossed for ya man.
Thanks E, my fingers are corssed too. Today they are looking Ok. Still growing pretty quick and it appears the new growth is better. Still too soon to say for sure, but I think they'll pull through fine. My flush ended up at 100ppm after a couple flood cycles which is no surprise. Those ebb and grow buckets always hold onto an inch or so of water. Next step is 200ppm, probably tomorrow. Then ever so slowly up. Live and learn...