Need help with diagnosis asap

[Burnout81]

It's my second grow n managed to rock iton first grow but seems this grow is a bit different. I'm getting yellowing on leaf tips and some minor brown spots on leaf tips. It's WK 5 in flower n looks like a nut lock out I would assume but what kind and how can I fix it. I get leaves yellow during flower but this is mainly tips n not whole leaf. It's under 300 w electric sky n I run FF 3 base plus boosters using there ocean forest soil in 10g air pots(bit over kill ik rookie error lol) day temp 81 night 68 hum 43%.

 

[hotrodharley]

Likely a potassium deficiency.

 

[Jypsy Dog]

Week 5... P/K issues will show.

http://catnews.org/FREE%20Pot%20Books/Marijuana%20Garden%20Saver%20%5b2005%5d.pdf

 

[Burnout81]

Likely a potassium deficiency.

I'm using a bloom booster Cha ching 9-50-10 do u think switching back to bestie bloom 0-50-30 will help correct this or is their some other way

 

[Herb & Suds]

Yup over doing it is a sure way to lock it up

 

[Jypsy Dog]

Water only...

 

[Burnout81]

So did a flush with and a light feeding of half dose of beastie bloom today hope it will fix the problem. I never pH my waste n decided to check it out and it was @ 5 so assuming that's how I got the deficiency