How It Works Start My Diary Login Sign Up
MrGreenFingers started grow question 3 years ago
How do I get on top of a phosphorus deficiency in veg as cant seem to shift it, new growth has yellow tips purple stems and getting some spotting and black patches on leaves, have been adding PK 13/14 at 1ml/l to the res for last few weeks which has slowed it down but not got rid
Spliff Cheese DWC
19 weeks
Spliff Cheese DWC MrGreenFingers
Spliff Cheese
27 comments · 2 years ago
Week 5
Techniques. Defoliation
Philindicus answered grow question 3 years ago
Stop using PK 13/14. Save this product for when your in the mid to end of bloom. Your part A/B should already have enough for your plants in veg. You definately have a PK excess. K blocks out magnesium. P blocks out iron, manganese,zinc or copper. It looks like you have either a magnesium or an iron deficiency or both. You can use Epsom salt(magnesium sulfate) as a foliage spray at 1 teaspoon per gallon add a few drops of baby shampoo as a surfactant. Spray every 4 or five days until she greens up again. Be sure to spray the underside of the leaves as best you can. Do this at lights out so the lights don't magnify the water drops leaving brown spots on the leaves. I she's not greening up you can do the same thing with an iron product or a product that contains iron. You may be able to use Epsom salt in your hydro solution but I don't know what the dose would be. Hope this greens your girls up good luck.
CrokuDodu answered grow question 3 years ago

Unlikely to bit a phosphorus deficiency indeed regarding what your feed her with.

My 2 cents on what I would try :

- stop the PK
- what's the stability of your EC ? Going up, down or stable ? The numbers seems a bit high (maybe due to the PK) but checking the stability of your EC will tell you the needs of your crops. Is the Ec of your tap water low or high ? If it's around 0.4/0.5 I might advise to reduce the calmag/silicon, but keep in mind that i'm not familiar with that nutrients brand.
- slightly lower the pH, around 5.8.

Good luck !