Yellowing leaves weak bud development in week 5 of flower

[Mike_3]

Growing in soilless media pro mix currently in week 5 of flower.
Anyone know Why are my leaves yellowing from the outer leaf as shown in the first picture? Also noticing slow growth and small bud? Is it to late to fix this? Any suggestions would be highly appreciated.

 

[tobh]

What's your pH? both going in and coming out. Any amendments we need to know about? How much are you feeding each feed? What about environment? Temps/RH? You have some purple striping on the stalks as well, so I'm leaning towards a pH issue locking something out.

 

[Mike_3]

My ph in is 6.3 and my run out ph is also 6.3 when I’m feeding. I was feeding at 930 ppm every feed. Now I’m feeding at 1100 ppm.

 

[Ponky]

Pro mix can sometimes get real acidic. So lime top dressing. Rinsing the media out thoroughly with a hose. Literally washing out the excess nutrients. Then start your feed program again. Another option is just to clear flush with water from now until harvest. If you're pro mix is over loaded with nutrient salts it can help.
Another method is humic and fulvic acid. Run just that in water.

 

[Mike_3]

Pro mix can sometimes get real acidic. So lime top dressing. Rinsing the media out thoroughly with a hose. Literally washing out the excess nutrients. Then start your feed program again. Another option is just to clear flush with water from now until harvest. If you're pro mix is over loaded with nutrient salts it can help.
Another method is humic and fulvic acid. Run just that in water.

I’m sure it’s not salt build up in my media I took run out with just ph water they actually were low on food. 500 ppm 6.3 ph out