How can you really know what's wrong with your plant?

It seems like most info you get is vague and convoluted, so how the hell can you really determine what's wrong and how to treat a problem?
For instance, my plant is in the 4th wk of flowering and most of the fan leaves are yellow or turning yellow. I've heard this could be lack of N or too much N.... which one is it!?
Here are some details: Temps-mid 80's, PH 6-7 (soil), ppms 1400-1500 (last feeding was a bit lower tho 1300-1400) AN-GMB-big bud-bud candy
Hopefully the pics will provide enough info for someone to help me out.

when plants flower they will rob fan leaves of nutrients. leaves yellowing and dieing off is normal. what i do when my plants start do that is when i feed with my flowering nutrients i add 1/4 to 1/2 str veg nutrients to the solution as well. that'll slow the yellowing down some.

If it was too much N, then your leaf tips would be curling under, like claws. I see some of that in a few of your pics.

yeah budds looking nice dude

personally i tear off fan leaves from now on with 50% + damage

try taking a pic as the lights have just turned off - u will be amazed how it cures the yellowing of leaves

buddwasher said:

yeah budds looking nice dude

personally i tear off fan leaves from now on with 50% + damage

try taking a pic as the lights have just turned off - u will be amazed how it cures the yellowing of leaves

Click to expand...

So ripping off any leaves that look bad cures yellow leaves? Awesome!

buddwasher said:

yeah budds looking nice dude

personally i tear off fan leaves from now on with 50% + damage

try taking a pic as the lights have just turned off - u will be amazed how it cures the yellowing of leaves

Click to expand...

lol its not just the color of the light that makes the leaves APPEAR yellow, they are yellow. and just tearing off leaves that are damaged doesn't solve the problem.

I think they look hungry.

Given the time of life, I'm voting for Potassium, Phosphorus, and Magnesium. Yellow leafs can be cause by more than just a Nitrogen deficiency and this does not appear to be nutrient toxicity to me.

Yet, you are feeding them plenty... so... Ultimately I have to agree this is just the natural autumning of your leafs.

cowell said:

So ripping off any leaves that look bad cures yellow leaves? Awesome!

Click to expand...

tearing off leaves that are damaged doesn't solve the problem

buddwasher said:

yeah budds looking nice dude

personally i tear off fan leaves from now on with 50% + damage

try taking a pic as the lights have just turned off - u will be amazed how it cures the yellowing of leaves

Click to expand...

Dont give anyone advice if its poorly effective and not correct at all.
Please only comment with sense and maturity.

JackBaneNapier said:

tearing off leaves that are damaged doesn't solve the problem

Click to expand...

LOL.. sure it does Jack. You must not have read the sarcasm in my post. The dude said he tears off all his leaves that are damaged looking more than 50%... says it cures yellow leaves.
if you tear off all the yellow leaves - of course you don't have yellow leaves. Brilliant Observation.

You of course are right - you have to get to the root cause of the yellowing to fix the issue.. I was having some fun.. thanks for keeping the info accurate.. that's important.

How do you know what's wrong with your plant? (Like that doesn't invite a sarcastic remark...LOL)

Aside from being a plant whisperer, I've found that posting pics on this site will help you get a myriad of different answers - some good, some not. Or you could simply check the pH and PPM to see if you're in the right zones.

it's also a good idea to check to see if:

*Your temps are good
*Your humidity is good
*Your growing medium is good
*Your grow room is clean
*You're following the nutrient directions

Yes, there's a lot that can go wrong in a grow and often it's not something that you can pin down. Sometimes, you just need to try a few things, see if they work, learn, and then try not to do it again on the next grow.

As for what seems to be wrong with your grow, looks to me like your plants need more nutes. But then again, some of those signs are the same as burn - at first glance.

I've found that looking at what you're doing first usually lets you know what you've done wrong. AFter that, post here (check, you've done that) and then I look at pictures in books like "Marijuana Horticulture."

Most of the time, it's a nute problem or a pest problem.

I think a lot of the answers you've gotten here are reasonable, so why not give them a whirl? Worst case scenario, you have to start again.

But you'll be a wiser grower for it.

(Also, make sure you give people on the boards all the information you can. Easier to diagnose when we feel like we're in the room with you.)

And NO don't pull off the leaves. That's just going to stress your plant out and it's already stressed. Unless they have bugs on them, leave them be.