Yellowing Vegging in Bat Mix

Here's my situation:

AK-47, week 8 of veg.
Potted up in Bat Mix (4-16-4) 4 weeks ago, suppliers say this has enough nutes for 6 weeks, so no other nutes.
Watering on a wet dry cycle, temps between 70-85, humidity 40-50%

I've got a little tip burn, but more worryingly a LOT of yellowing / dead leaves.

I've 2 other AKs in exactly the same system with some similar symptoms, but they are very mild and I'm not too fussed. Interestingly this plant is much more sativa looking than the others.

The plant looks hungry to me or is it just burn? I've not seen such N depleted leaves from nute burn before...
Obviously I can feed if its hungry but if the soils just too hot I'm fucked aren't I?
Any ideas?

What is your PH? And what do you water with? Tap, distilled, RO?

looks like nute burn to me. burnt tips. r u using nutes? if not then ur soil is too hot. i dont see any perlite or any theing. i mix 3 parts dirt to 1 part perlite and 1 part pete or i like happy frog soil amendment. it cuts the dirt so it aint full strength. good luck hope this helps

PH going in is 7, it's tap water, very hard so lot's of Ca, could that be related? I've noticed some stripy leaves too and did consider Mg lockout as one part of the problem...
And no nutes so far. Mixing down the dirt makes sense for the future, but the roots are established in the Bat Mix now, is there anything I can do for this plant? :S

flush..................... and find out your soils ph

i agree with max

The soils pH is 5.8-6.2 according to the supplier.
Will flush and take a runoff measurement when I get home.

Am I right to be aiming for pH 7 runoff with soil?
What can I do to fix this if it's off?
I've read that soil buffers a lot so it's tricky adjusting the pH with water etc...

Once you get your PH figured out you need to start to feed her look at her purple stems. I would stop adding the cal unless you have experience with that being a problem. What will you be feeding her?

Don't worry about the runoff, and that soils ph seems a little low. Must be for an acid loving plant

My tap water is naturally high in calcium, I haven't added any. Filtering it out is an option but it lowers the waters pH to <6 so I haven't to date.

What are the purple stems indicating Sparkafire?
You don't think it's burnt like the other guys here?

And yeah Max I thought that was low. The soil was recommended on another grow forum, it's designed for weed too so I'm surprised tbh.
Do you think it could be causing lockout?

muckleby said:

The soils pH is 5.8-6.2 according to the supplier.
Will flush and take a runoff measurement when I get home.

Am I right to be aiming for pH 7 runoff with soil?
What can I do to fix this if it's off?
I've read that soil buffers a lot so it's tricky adjusting the pH with water etc...

Click to expand...

i like my runoff around 6.0. if it gets too much higher it starts locking out nutrients. also just because it was manufactured at a ph of 5.8-6.2 doesn't mean it will stay that way. adding nutrients and water to soil will almost indefinitely change its ph, especially in cheaper soil as they tend to use less PH buffers. flush the plant with plain water, and test the ph of the runoff water.

You have a Phosphorus lock out and your plant has used up the N in the soil. Yellow leaves Purple stems. No you do not have nute burn.

RRLBT420 said:

i like my runoff around 6.0. if it gets too much higher it starts locking out nutrients. also just because it was manufactured at a ph of 5.8-6.2 doesn't mean it will stay that way. adding nutrients and water to soil will almost indefinitely change its ph, especially in cheaper soil as they tend to use less PH buffers. flush the plant with plain water, and test the ph of the runoff water.

Click to expand...

Please explain the 6.0 PH My understanding is that soil should be in the mid 6's to very low 7's

sparkafire said:

Please explain the 6.0 PH My understanding is that soil should be in the mid 6's to very low 7's

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this is simply a matter of opinion. pot plants can survive nearly any ph from 4.0-7.0, but ideally should be between 5.8-6.5, as outside this range you do lose some nutrients.

RRLBT420 said:

this is simply a matter of opinion. pot plants can survive nearly any ph from 4.0-7.0, but ideally should be between 5.8-6.5, as outside this range you do lose some nutrients.

Click to expand...

Thank you for that

I have to diagree with you on the low ph, only because I have delt with it first hand and witnessed it first hand. I'm not saying 6.0 doesn't work for you but in most cases that is too low (mainly in flowering). Certain nutes get locked out with soil ph that low. Maybe not completely locked out but aren't as available is what i should have said

Just measured my runoff at 6.2, which looks good on that chart, I'm thinking the problem lies elsewhere.

sparkafire said:

You have a Phosphorus lock out and your plant has used up the N in the soil. Yellow leaves Purple stems. No you do not have nute burn.

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What's locking out the P?
The soil is 4-16-4 so there's plenty in there.
I wanna add some ferts with more N (got some Bio Bizz Grow) but as the soil is pretty hot I was worried about burn.

max316420 said:

I have to diagree with you on the low ph, only because I have delt with it first hand and witnessed it first hand. I'm not saying 6.0 doesn't work for you but in most cases that is too low (mainly in flowering). Certain nutes get locked out with soil ph that low. Maybe not completely locked out but aren't as available is what i should have said

Click to expand...

where'd you get the chart? in all the charts i've seen, 6.0 is an acceptable ph range for either soil or hydro, including your chart which shows how iron and manganese are locked out at 6.5View attachment 1607332View attachment 1607334View attachment 1607335

yahoo, listen im not arguing all im sayin for me low ph of my soil caused a magnesium lockout in flowering. And like i said im only speaking for myself

Haha seems pH is a touchy subject. Don't think Mg is my issue though so it's gotta be something else....