Need help

[Daiseysue]

Need help...first time grower. Have a couple autoflowers growing out doors. Something is wrong on 2 of the plants there leaves are turning yellow brown. Possibly spider mites?? On my other 2 plants which are a different stain the leaves are discoloured. I use rain water on them and have a nutrient system I feed once a week. Could there be a Deficiency?
Thanks
Suzanne

[duckman]

one possibility...https://www.growweedeasy.com/yellow-...-leaf-septoria

[duckman]

and another possibility would be a calcium issue https://www.growweedeasy.com/common-nutrient-problems

[Canuck147]

Could also be spider mites - look under your leaves.