Third time not lucky.....

[Willie72]

I am on my third attempt at a grow and it's going wrong again.

I have a Royal Jack growing in a mix of plant magic soil and cocco, I have been using plant magic soil grow as feed in the water at lowest suggested level of 2ml per litre and my plant is not looking good in week three.
The Leaves are yellowy, including the freshest growth, and the lower leaves are going brown and curling up. I think it might be magnesium efficiency but ain't sure.
Can anyone help?

 

[namvet25]

What kind of nutes are you using,npk value and what dosage?

 

[Willie72]

This is what I'm using and initially at 2ml per litre but the last batch I made was at 4ml per litre. I have also added a small amount of Mamoth P as I saw somewhere it helped with bacterial levels in the soil.

 

[Waira]

Something is way wrong with that soil blend most likely,... Coco has no significant nutrition, and the soil isn't enough by itself either.. Blends make a bastard child that are not balanced in either nutrients or performance.. stay away from coco until you've learned more about it, custom soil blends like this often as not go south! Coco itself is a challenging soilless medium....
What nute brand is that? It's very weak in NPK, maybe that what you're using isn't enough...
Above all this, you need to get the in-pot pH figured out, everything hinges off of that. Off pH locks out nutrients....
Now, unless you have a good pH probe (like the Accurate 8 soil pH probe) to test directly in the pot, you're stuck with either run-off testing, which needs to be done right and even then it's a rough estimate (there's an how-to in the Sticky article section above this one), or a slurry test. You need a good working pH meter for that.... Let me know if you want to try this,...
At week 3, it's late in the veg' game, and even if you save them, they will not yield much since blooming is soon to start....something to consider!

 

[Willie72]

The brand is plant magic. I used the coco to bulk out the soil mix I had. Should I will try a stronger NPK mix nutrient?

I'm gonna test the ph run off. Here's hoping I can fix things.

 

[Willie72]

The run off test seems to indicate a ph of around 5.
How can I address this?

 

[Waira]

The run off test seems to indicate a ph of around 5.
How can I address this?

Well, that depends a great deal on exactly how you did this run-off test... Run-off isn't an reliably accurate way to measure pH in true soil generally speaking, but if done right can give a rough estimate...And it has to be done a certain way to avoid any skewing of result reading due to other things influencing the pH of the r-o; hard water, Ca-Mg will skew the results making them more inaccurate, because the carbonates will buffer the pH. There's a Sticky article in the section above this one that shows an improved method for this.. You have to use just plain water, unadjusted, RO/Di/very low ppm which have those buffering minerals removed...
What was the pH going in? Pure water, not a nute solution? Not adjusted? this is part of how you compare the readings to determine the pH estimate in-pot, that 5.0 is not the actual pH, but being that low indicates a problem that will require a flushing most likely... What's you water source, pH, ppm?
With that mix, I'd use a weak Ca-Mg solution, low ppm water, made up to about 150ppm; usually 2-3x pot volume of this water is put through to purge the excess salts and help correct pH; measure the pH and if you can, ppm of run-off a few times after starting to see how it's progressing... collect r-o in a clean container... get pH up to around 6.3 and ppm 500-ish; you can then make up a L or so of weak nute solution, pH adjusted, and put it through to restore some nute content balance...

 

[Willie72]

I pretty much followed the instructions in the sticky.
Can't remember the run off oh but the plain water going in was around 7.8.
Gonna give it a couple of days then if no improvement then pull it and try again.

 

[LazyNhazy]

That medium looks super dry, coco must stay wet in order to work correctly.