whats happening here?

hi everybody, can somebody tell me whats wrong with this plant please? I've read the problem pages and deficiency guide and from what I've read its not getting magnesium but it could be a couple of other things too so I thought I'd ask and maybe one of the well experienced members will know exactly what's wrong, they are 21 days into flowering and are ak47, they're in soil, they get watered twice a day with normal tap water and the ph is about 7, the lights far enough away, they've got good ventilation and good water drainage,

whats happening is the bottom fan leaves are getting a browninsh rash on them which is getting worse and then these are dying, and then as you go up the plant this goes away but then the fan leaves half way up and near the top are a lime green colour not a nice dark green, and they're yellowing and browning around the edges and curling up over? its happening more to 2 of the plants but the others are getting the rash on the bottom leaves too? a few leaves turn shiney aswell? why does that happen?

I'd be grateful for any help, sorry about the pic, the light makes my phone go funny, I must add this is for personal use only cos I got sick of funding asshole dealers for shitty amounts, I love the forum its great, I love reading about peoples grows and stuff its really interesting, thanks for reading

You need to check the pH of the the soil and adjust it to 6.5. It's hard to say much more without pics of the lower leaves and their brownish rash. There is some deficiency there but most of it is probably caused by the pH. Once that's fixed, you'll be able to see what you're really not giving them enough of, if anything.

heres a couple of pics of a fan leaf from the bottom end of the plant, I'll get a soil ph tester later
thanks for the help

Adjust your ph to 6.5 then water/feed. Do a foliar spray with mag/cal just for gp.

So just water twice a day? no food.. what kind of soil is it?

That plant is under water stress too....Read Uncle Bens thread at the top of the page.

right I'll get the ph sorted and see what happens and get reading that other guide, it seems to be more specific, yeah I just water twice a day, l would start giving them a bit tomato food at week four because I think theres enough food in the soil to last till then? I let them use whats in the soil first, the soil is john innes no 2 for repotting flowers and vegetables, I veg them in little pots first then when its time to flower I repot them into big pots, which is why I get the repotting soil, I've used it before and had great plants without any problems but this time these couple of plants arent happy? cheers for the input everybody!

seasmoke said:

That plant is under water stress too....Read Uncle Bens thread at the top of the page.

Click to expand...

actually, I've wondered that, when I water them I pour the water in and it doesnt go into the soil very quickly? could the soil be too compact and not airy enough, would it be better if I water them say 3 to 4 times a day with less water instead of 2 big waters? will do, cheers

this is the exact problem ive been having and asking for help and have had no one answer with a solution i believe its my fault not explaining it as well as T P T But i hope this helps a little been studying this for 24 hrs now i came up with magnanese deficiency and finally got a ph meter and reading 4.7 others are 5.3 some plants are worse than others the worse being 4.7 I read somewhere manganese is locked out between 2.5-5.0 ph

Tony, how big are your pots? Are they heavy when you lift them? Is the surface of the soil hard and crusty? If it is, break it up and loosen it. Then add a little Palmolive soap to the water you give them, this will help with draining. If pots are heavy, then let them dry out a bit...don't let the leaves droop, water if they do.
Read this_

https://www.rollitup.org/marijuana-plant-problems/150004-plant-moisture-stress-symptoms-solutions.html

(I am in 5-gal buckets, 4-1000 hps lights, temps 65-70 nite time 70-80 daytime, Rh 30-50%. I water every other day( when pot starts to lighten up) until there is run off.

tony the pony said:

actually, I've wondered that, when I water them I pour the water in and it doesnt go into the soil very quickly? could the soil be too compact and not airy enough, would it be better if I water them say 3 to 4 times a day with less water instead of 2 big waters? will do, cheers

Click to expand...

A few drops of dish soap in your water can help break the surface tension. Helps the water ease into drier soil.

If you just add a cup or two, then let it soak in, you should be able to give it a good full watering an hour or so later.

EDIT---^^^^didn't see the post above this one before I replied^^^^^

But if I may add to seasmoke. Just because leaves droop, doesn't mean underwatered all the time. It can also be a symptom of overwatering.
I have found this to be the best guide online I have found as of yet. Covers nearly every issue plants can have from nutes to pests.
International Cannagraphic Magazine Forums-The Complete Guide to Sick Plants, pH, and Pest Troubles