I Need Help Diagnosing A Problem

[sharprock]

First grow.

It is only effecting one of my three plants in an RDWC system. It started about 2/3 the way up the plant and moved up. I initially thought leaf spot fungus of some sort and sprayed with a mild sulphur solution but that did nothing. Now I'm thinking Calcium deficiency. I just picked up some CalMag+ and changed out the nutrient solutions for plain PH 6.5 water with 1ml/Gal CalMag+. I thought I'd try that for 24-48 hours to flush the plants. The tips are starting to go brown so there could be nutrient burn.

Its been 12 days since it started and it has yet to spread to my other two plants. Is this plant salvagable or should I cull it? The plants are 5 weeks into flower.

Growroom Conditions: Humidity 55-70%, Temp 25-27C, PH 5.8-6.0, EC 2.1-2.3, Growroom Size is 39" x 117", Ventilation Fan is ~100CFM

 

[Jack og]

Let it ride bro, signs show the deficiencies are far and there is no coming back at this stage, keep a light feed as normal and let her finish out.
Check the roots to see if it looks rotted or burned ?
I’d keep her going and it is common to get some sort of issues

 

[sharprock]

Here is a microscope image.

I will check the roots in a day or two.

 

[crimsonecho]

They look dark what are you feeding them. They seem to suffer from nitrogen toxicity. I mean they are dark green. The other spots and burns could be caused by too much nitrogen maybe, brainstorming. There could be lockout and nute burn issues caused by toxicity? Maybe?

 

[sharprock]

They look dark what are you feeding them.

I think thats just the lighting. This photo was taken with my cellphone with lights out.

For ~18 Gallons:
110 ml Bloom
75 ml Micro
30 ml Gro
20 ml Silica
1 Tbsp Epsom Salts

My tap water is a bit hard 250 ppm or so. The resultant EC is about 2.1-2.2

 

[crimsonecho]

I think thats just the lighting. This photo was taken with my cellphone with lights out.

For ~18 Gallons:
110 ml Bloom
75 ml Micro
30 ml Gro
20 ml Silica
1 Tbsp Epsom Salts

My tap water is a bit hard 250 ppm or so. The resultant EC is about 2.1-2.2

I am no hydro guy but someone will help based on your nutes i am sure. I just see the bud at the right of the yellow leaved one and it looks very dark and the tip of the leaves are looking downwards and the bottom leaves are looking like they are clawing too.

 

[Jack og]

Did it at anytime have pm issues? The necrosis along with what lolooks like a nitrogen burn maybe what’s showing the issues. Leaves definitely look like they are dying but like I said the plant being this far out, it should still finish. Doing too much at this point will ruin the harvest.
Also what’s the ppm after mixing including the water hardness?
May wanna cut back on cal mag with That hardness.

 

[sharprock]

I presume you meant PH issues. The plant used to be right next to my resevoir and sometimes I would add PH down directly to the resevoir and turn on the circulation pump. That could have resulted in PH in that first bucket dropping quite a bit before things got mixed up and maybe that caused some root burning. The symptoms first appeared within days of me doing a fairly large PH adjustment in that manner.

I'm trying to maintain my EC at around 2.2 right now after water hardness. That would be about 1320 PPM according to my meter. I was using Walmart Epsom Salts because I figured the water probably had enough Ca. There might be an additive in Walmart Epsom salts that I don't know about. I just switched to CalMag yesterday to do this flush.

The other two plants look healthy and they all share the same nutrient solution. Its been 12 days since it started and its not spreading. I'd just like to figure out what my mistake was so I don't make it again.

 

[sharprock]

If anyone is interested, this issues was a calcium deficiency. I switched from Epsom Salts to CalMag and the leaves are starting to green up again.

I remember reading somewhere that you have to maintain a calcium to magnesium ratio and that increasing one will increase demand for the other. So I figure that adding Epsom Salts is out unless you're also adding calcium. I figured I would have enough calcium in my hard water. Apparently not.