Phosphorus deficiency?

What type of soil are you useing? Are you useing fox farm happy frog? I know this is a very common soil people use. If so the happy from ph start at around 4 and when you go into flower the low ph will make it look like that from lack of nutes. ( generally I would say it's a ph problem, check your run off water and adjust feed water to fix ph inbalance. lf the ph is to low you can just flush the pot with a bunch if tap water usually tap water will run between 6.9 to 8.9 ph usually can pull the ph back up with a few gallons of

Looks more like potassium and calcium. What could also be caused by a ph issue or other root related issue in regards to feed and amount of water.