Possible sulphur deficiency?

345 grow guy

Active Member
I've got 2 C-99 about 4 weeks old that have started rapidly turning yellow on top and the upper leaves are curling upward. They are in soil with a decent amount of DTE amendment and are watered with RO water supplemented with Bloom City Cal/mag and Silica booster. Soil pH seems good (not the best pH meter) 6.8 - 7.1ish and I water with 6.8ph. They are under a 2ft 4 bulb T5 but currently only 2 bulbs are on. I turned 2 off at first thinking it was some kinda light burn or bleaching but I'm sure it's not anything to do with it.
I've been reading through the plant problems thread for the last 3 days now and the best I can come up with is a sulphur deficiency because it's only on the upper new growth and it's about the only thing I haven't added amendments for. Let me know what you guys think it is and what's the best way to remedy it.
 

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rkymtnman

Well-Known Member
i highly doubt it's sulfur deficiency.
i'm not a dirt guy but looks like N deficiency. or something causing an N deficiency.
 

pulpoinspace

Well-Known Member
sulfur would be easy to fix. add 100 ppm epsom salt. takes care of mg too. but without knowing your soil and what amendments you put in its impossible to say. those symptoms could be iron, calcium, copper, zinc, potassium, phosphorous, pH, light burn.... definetely some cupping in that 2nd picture looks like heat/vpd issue

what is the soil and what amendments did you put in?
 

345 grow guy

Active Member
sulfur would be easy to fix. add 100 ppm epsom salt. takes care of mg too. but without knowing your soil and what amendments you put in its impossible to say. those symptoms could be iron, calcium, copper, zinc, potassium, phosphorous, pH, light burn.... definetely some cupping in that 2nd picture looks like heat/vpd issue

what is the soil and what amendments did you put in?
The soil is a mix of compost, worm castings, coco coir and a little perlite. The amendment are DTE All purpose mix, Alfalfa/Kelp/Crab meal and a little Bio-live in a 2.2 gal autopot. It's not the first time I've run this mix on C-99. The first run went well but needed some calcium supplement, which is why I added the Bloom City and don't think it's calcium. I also don't think it's heat or light stress because it has been over 78° in my veg area and I've actually only been running on 2 bulbs (like 50 watts).
 
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345 grow guy

Active Member
i highly doubt it's sulfur deficiency.
i'm not a dirt guy but looks like N deficiency. or something causing an N deficiency.
The only reason I don't think it's N deficiency is because it's only on the new growth. Nun of the older leaves are affected. To be fair though I am not a seasoned grower (5 or 6 grows) and really only know what I've read online.
 

345 grow guy

Active Member
My guess is they are swimming in water down in the root zone and starved of oxygen. Too much pot for the plants size. Just my thoughts, could be wrong.
That is something I haven't thought of and you might be onto something. This started happening after I feed them last week and my water level really hasn't dropped any. I just thought they stopped drinking due to deficiency going on.
Luckily I'm using an Autopot and can drain it pretty easily. I'll actually go do that right now lol.
 

Bobby Long Buds

Well-Known Member
That is something I haven't thought of and you might be onto something. This started happening after I feed them last week and my water level really hasn't dropped any. I just thought they stopped drinking due to deficiency going on.
Luckily I'm using an Autopot and can drain it pretty easily. I'll actually go do that right now lol.
Sounds good I’m not aware of how auto pots work. I suggest starting another couple seeds you may find they catch up and pass that other plants. Especially if your seeds are not from an expensive breeder.
 

danjac82

Well-Known Member
The soil is a mix of compost, worm castings, coco coir and a little perlite. The amendment are DTE All purpose mix, Alfalfa/Kelp/Crab meal and a little Bio-live in a 2.2 gal autopot. It's not the first time I've run this mix on C-99. The first run went well but needed some calcium supplement, which is why I added the Bloom City and don't think it's calcium. I also don't think it's heat or light stress because it has been over 78° in my veg area and I've actually only been running on 2 bulbs (like 50 watts).
You should not be seeing deficiency at that size with the amendments and ferts you’ve mentioned with such a small plant
 

345 grow guy

Active Member
You should not be seeing deficiency at that size with the amendments and ferts you’ve mentioned with such a small plant
Right? I don't make my veg soil very hot but I try to give it a decent mix of things. The soil had been wet for longer then I like so I drained it last night to let it dry out a bit. When its good and dry I'll give them another tea feeding with some epsom/gypsom and a few other things.
 

danjac82

Well-Known Member
Right? I don't make my veg soil very hot but I try to give it a decent mix of things. The soil had been wet for longer then I like so I drained it last night to let it dry out a bit. When its good and dry I'll give them another tea feeding with some epsom/gypsom and a few other things.
Sounds good. What amount of water do you use?
 
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