Yellow tips for the last 2 weeks

[Michael Gilmour]

My pal is growing some rhyno ryder from FB, biobizz light mix and using tangs easy schedule under a 600w mh lamp, temps are around 27c.

Hes having this issue with yellow tips. I've compared it to a few similar threads but others seem to be more "burnt" or across more of the leaf. This is just bright yellow tips mainly on new leaves, been going for about 2 weeks like this (have done plain water feed and no change). Any advice or help would be greatly appreciated!

Possibly light burn?

 

[Joemac879]

What’s the PH of the water?


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[Michael Gilmour]

That's the one thing we can't measure as we don't have a pH meter But using pH perfect nutes if that helps

 

[Joemac879]

That might be what your problem is.. from the looks of those pics that looks like a PH issue.. So you weren’t able to PH the straight water? A PH meter is imperative to have


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[Arthur]

Have seen pH perfect go sideways more than once. And have seen several run without an issue... kinda wonder if it is the water in some locations...


There is a chart @ the top of the infirmary, to give you a diagnosis as opposed to a guess we kinda need all the info..

Yellow tips can be caused by several things, deficiency, toxicity... or being unable to take up nutrients due to a high or low pH...

I'd bet your dealing with a lock out issue

The curving of the tips lead me to a calcium deficiency, but as to why... not enough? Or just out of pH range?

 

[Michael Gilmour]

Have ordered a pH meter and will check tap water and run off. Although I've read a lot of stuff about not adding pH up or down to organic soil?

 

[Arthur]

Have ordered a pH meter and will check tap water and run off. Although I've read a lot of stuff about not adding pH up or down to organic soil?

You should always ph your water/feed, you won't add directly to medium. You will have to "adjust" soil ph over time by adding an up that buffers the acids. A limestone based up would be great, as it will sit in the medium and buffer the peat etc breaking down into a more acidic mix.

Idea is if your high you shoot a little low so soil ph drops slowly...

Or vise versa going low to high.

If my soil is 6.2 and I am trying to hold 6.5 I may bump to 6.7 to try and increase the base of the medium.

Do not use my numbers, I run an organic nute line that is calcium based so my pH numbers are way high for salt based nutes.

Both my pH up and down are mineral based and OMRI compliant.

 

[STILLSMOKIN]

Looks like light burn on one and nute burn on rest

 

[Waira]

- that's looking like a Zn defc.,... yellowing only on top newest growth. tip edges in,... may star interveinally soon too.. Zn is immobile within the plant, so that's why it hits newest growth first as worst,... So, unless the soil pH tests out over 6.8+, then very likely this is a simple lack-of type defc., not a pH lockout; you will need a proper dedicated supplement to deal with this, more base nutes isn't likely going to cut it,... Do you know if the water you use is very hard?
Although it's too late since you ordered already, the best lower cost unit for in-pot pH testing is the Accurate 8 (Control Wizard products),.... is the one you ordered the really skinny metal probe kind? those are of dubious accuracy,....
AN stuff is "pH perfect" while in solution only, all bets are off once in the pot, just too many other strongly influencing factors going on in there... any other buffering will depend on if the medium mix has any lime in it,.... Organic doesn't mean pH bullet proof by any means.. Most products don't recommend pH adjusting the feed solution itself, and organic can be more pH stable than synthetic (which tends to be pretty strongly acidic), but you also need to have solid soil microbe scene going on in there, they are key to breaking down and cycling nutes in available forms,... Inoculants are really important!

 

[Michael Gilmour]

So thanks for all the help. I've checked pH, it's 6.2 with all the nutes. Now he's got yellowing leaves at the bottom, only day 33.

They are also pretty small at 45cms so not sure what is going on with them

And yes it's quite hard regarding the tap water