What is going on with these plants?

[Budget Buds]

Northern lights strain in a living organic soil, i amended with an organic fertilizer , all was going well but about 3 days ago the leaves started showing this, theyre isolated on the lower/middle growth , all three plants are showing the issue. pretty new to soil growing so any insight is greatly appreciated

 

[TanzanianMagic]

I'd need more information - pot size, temperatures, medium, nutrients used, pH and EC or PPM.

Whatever the cause, it is showing up as a Phosphorus deficiency or lockout. Considering the short internodal space on the plants, the wrinkling of the leaves, there may be some other environmental factor going on, like low pH, overwatering, etc.

So I'd l like to know:

- medium used
- EC or PPM
- pH the medium, nutrients, tapwater
- nutrients used