4 weeks into flower. Minor problem

[Random941]

Just staryed week 4 of flowering.
6 plants all close to six feet in height.
5 gal pots
Pro mix soil
15-15-30 nutes
1000w hps light
Ph allways 6.5
Constant 75-80 degree F
12/12 light cycle
FIrst grow
Sorry no pics unless someone can tell me how to upload from iphone
Water onece weekly nutes every second week

Everything was going great. Tied them down about 14 inches from the top budding really nicely. Last thursday i stepped my nutes up to half dose of the 15-15-30 nutes im using and just the other day i noticed that the very tip of some leaves are curling upwards and turning crispy, only a quarter inch of the leaf is doing this. It doesn't really seem too serious but i am wondering if i should back off on the nutes just a little or what.

 

[Random941]

Forgot to mention strain. Strawberry diesel.
Another question does tempeture have to change between day and night light cycles?

 

[OrganicTreees]

if its the tips that generally indicates your nutes are too strong.. Give them a bit of a flush and back off the nutes a bit and you should be good.

pics would help though

 

[Vampire]

Yes def. back off on nutes and flush the plants out. Also, flowering plants need higher P, the second # like 15-30-15. It's good for them if it gets cooler at night but as long as it stays in your temp range no problems should arise. Good Luck.

 

[Ganjahoarder]

How close r ur lights. Might be heat stress. Also, the temp, r u taking the reading from the canopy or floor.

 

[Random941]

The light is one foot away and temp reading is four feet from ground

 

[Ganjahoarder]

With a 1000w hps, I would back mine up to 20-24 inches. Thats what I have my 400 hps at and it still gets hot.

 

[Random941]

I have a fan constantly blowing over the tops of them. The leaves that are doing this are 2 feet away from light

 

[Random941]

Would i be better off with 15-30-15 rather than the 15-15-30 i am currently using? And could i combine the two together so that the second two numbers are both higher than the nitrogen?

 

[OrganicTreees]

you could definitely mix the two to get the K value higher.. Cannabis likes K almost as much as P

 

[Sam Spade]

This sounds like it could be a magnesium deficiency -- I just dealt with this problem myself Help! leaves turning white/pale on edges and curling upwards. Does your plant look like mine did? The leaves were turning upwards and the green color was disappearing from the leaves.

Are you using tap water in your grow? I think using tap water was my problem. Adding epsom salts to your water might do the trick.