White widow 10 weeks from sprouting
5 gal fabric pots
Organic soil with worm castings
FF nutes
Watering 2x a week 1/2 gal each (1 feed per wk)
SF 4000 light at 40% - 20” from top
RH 50-55%
Temp 70-75
Plenty of air flow
Ok, I have been feeding these since about 4 weeks old. I started with a 1/2 nutrient dose with the big bloom, grow big, cal/mag always ph’ed around 6.3-6.8. They did fine. Ok, so I went up to a full dose (according to the FF nute schedule). Only feeding ONCE per week 1/4 gal per plant. (I use sledgehammer every other week at my reg water feeding). They were doing fine and I saw some rust spots on the top growth. I assumed it was light burn since I have been giving plenty of cal mag. So I turned light down. New growth had no spots, thought it was fixed. A week later I was seeing even more spots, so I was thinking this must be a problem with the ph at the roots or the PPM. So I checked run off ph. It was within range. PPM run off was 2000-3000!!! I had been inadvertently been feeding them really heavy (1500ppm) and didn’t realize they were having build up. I assume the cal mag rust spots are from salt build up causing it to lock out the cal mag. So I flush. A few gallons each regular ph’ed water. This brought PPMs down into the 900’s where they should be. The day I flushed was a feed day so I skipped feed that week (this was the Sunday before last). Put a fan on the pots to get them dry within the 3 days, come Wednesday they were thirsty again. I used reg water to get a run off reading again. The ppm was back up to being super high. My thoughts are I was not watering enough quantity and they were over drying which created the nutes to become immobile like that. So I flushed them Wednesday last week. Big mistake! By the Sunday after this (4 days after flush, this was this past Sunday). They were pale and looked horribly hungry. I fed them a 900 ppm 1/2 gal each mixture. They seemed better but they are still pale and yellowing. One looks just yellow and pale and another looks like it has a cal/mag or zinc deficiency. It’s got the dark veins. These were supposed to be easy to grow and they have been a giant pain in the ass. The last strain I grew loved the feeding schedule I was using (same as I tried here). I want to flip these to flower but they need to get healthier and back on track. I’m at a loss at this point and all I can think is they are just malnourished, for whatever reason. I can’t imagine flushing them with ph’ed water would throw their ph out of whack since then. Sigh. Please help.
I’ve had the best luck when using FF nutes by feeding only 1/3 of the recommended dose in only 1 gal of RO (when feeding 2.5 gals) every other watering. Any more usually leads to nute burn. I avoid most flushes, runoff PPM is well-managed, and I get good yields.
If pH is an issue, then a flush will usually cause runoff pH to revert to 6.5 in Fox Farm soils.
Sledgehammer will strip the nutes out of your medium.
I’m not sure of the nutes and the medium your using but I would suspect sledgehammer may have something to do with your issues.
@MidwestGuy knows his stuff but I also agree with @Brobdab which in that case adjusting nutes like MidwestGuy said may take care of it.
I had a plant that looked like that in coco and I added some Epson salt and it helped and turned the leaves back green. I would try MidwesternGuys suggestion first.
Good luck!
They look hungry if you ask me they look like they asking for a lot of water at this point , nutes on soil must be running low , where they doing good before ?
She needs magnesium pretty quickly. Epsom salt is going to be your best move. Sledgehammer is meant for every 4 weeks after you start feeding synthetic nutes. Not every other week.
Feeding 1/4 gallon for a 5 gallon pot is not feeding. It is snacking. It should be getting a full gallon to a gallon and a half depending on the stage of the plant. And that’s likely where your deficiency started.
All those ppms were probably from the organic soil and worm castings. Which were rendered useless by the sledgehammer basically making your soil inert.
Fox farms nutes are light on magnesium so you’ll need to add epsom salt into your routine.
Yes they were doing just fine. I agree they look hungry but what made me wonder is why showing signs of nute burn and high PPM run off before. Maybe I swung from one end to the other (way over fed to way under fed).
Yes epsom salt is in all my regular waterings I had soil flies from overwatering before (last grow) so I backed way off on the water. I do give them 1/2 gal right now but I’ll up to 1 gal.
Got it, thanks! That makes perfect sense as to why the PPM readings were so high and why they looked hungry as soon as I flushed them. Stupid mistake on my part. I guess I thought that’s the reason why they looked burnt but really it was a magnesium deficiency. Which I have dealt with in the past. I should have known but I thought I was giving them plenty- like you said not enough water/food for the size of the plants.
