Over fert or potassium deficiency ?

I'm growing Purple Maroc from female seeds outdoors in 5 gallon self watering containers. Starting with 4 seeds, I did an Uncle Ben's top to induce 4 main stems and then went on to root the 4 pinched off tops and am also growing those as well . This is my second year using self watering buckets with good success last year just using some bag seed.

We're on well water here in the county that shows ~315 TDS. Wells are sunk into dolomitic limestone so the water is probably rich in calcium as well as perhaps magnesium. The water's PH tests ~ 7.3 out of the well and I adjust that down to ~ 6.3 with PH down. Early on the plants seemed to be nitrogen deficient with many yellow lower leaves and the upper leaves lighter than would seem optimal. I was initially using 1/2 tsp/gallon of Jack's Classic 20-20-20 but say limited response. Over time I slowly increased the the dosage to a maximum of 1 1/2 tsp./gallon of water. Now I'm seeing evidence of either nutrient overdose or potassium deficiency on some but not all of the plants. Interestingly, the 4 tops that I rooted and planted in some recycled Lamberts LM3 medium that contained some Osmocote from some veggies I started the year before but scuttled before their roots pervaded the medium look great and show no signs of burn and were never yellowish. I'm wondering if the Osmocote is providing something that the plain Lamberts is lacking.

I've flushed the media of the most burned looking plants with PH adjusted water and stopped feeding them for the time being. If this is a potassium lockout then hopefully there is something I can do for that too.

Here are a few pictures. I'm hoping the burned looking plants can be salvaged. They're just now starting to bloom. Thanks for any advice. I'd really love to save these girls.

I think its a good idea to re pot. The pots are far too small for those plants. The nute burn is salt build up because the medium is drying too quick.

Idk about salt build up..

But yes your ec/ppm is too high. Over fert is a possibility. Too small of pots is a possibility. Probably both.
Also i dont like the npk of that, equal levels isnt ideal.

*BUDS said:

I think its a good idea to re pot. The pots are far too small for those plants. The nute burn is salt build up because the medium is drying too quick.

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Thanks for the reply. These girls aren't going to get repotted at this point. They've sunk their roots through the hundreds of holes between the media holding bucket and the water/nutrient bucket below. They're also flowering now so will need to ride out the problems as best they can. It looks like I'll need to sort this one by trial and error.

Hopefully the I can salvage the gals that look to be burned.