why you need potassium

Potassium plays a big role as well. Having good amounts of potassium in your plants helps in having sturdy and thick stems, disease-resistance, water respiration, as well aids in photosynthesis. Potassium is also found in the whole plant. It is necessary for all activities having to do with water transportation. Potassium is necessary for all stages of growth, especially important in the development of Buds.

Having to little of Potassium in your plants causes the plants leaves to show retarded growth and show a scorched tip and edges around the leaves. Plants may stretch and your branches can be easily broken or weak. Don’t get this deficiency confused with iron, because it almost acts like iron but to tell the difference in the two is: for potassium the tips of the leaves curl and the edges burn and die. Older leaves may show a red color and leaves could curl upwards. Dead patches (Necrosis) can happen on the margins of larger fan leaves thus, the leaves will eventually die off and turn brown. The Older leaves will show different patches of color (mottle) and turn yellow between the veins, following by whole leaves that turn dark yellow and die. The plants overall growth slows down, mostly when they are in vegetative stage. To little amount of potassium also slows the growth of buds during flowering stages. Dark edges will appear around the edges of the leaf when the deficiency is starting to happen. When your Relative humidity is low, you can almost bet your going to soon get a potassium deficiency from your plants perspiration.
Potassium can get poorly absorbed when having too much Calcium or ammonium nitrogen, and maybe cold weather. Having to much sodium (Na) causes potassium to be displaced. SO keep those in mind… Parts affected by a Potassium Deficiency are: older leaves and leaf margins.


When you have too much Potassium in your soil, it can lead to big troubles, like salt damage and acid fixation of the root system, as well as too much potassium can cause a calcium deficiency. Your fan leaves will show like a light to a dark yellow to whitish color in between the veins. Due to a molecular imbalance, potassium toxicity can cause a reduced uptake and lead to the deficiencies of Mg, and in some cases, Ca. Also leads to the other nutrients to not be absorbed properly leading to lots of other deficiency such as: magnesium, manganese, zinc and iron and can cause problems with calcium as well.



Problems with Potassium being locked out by PH troubles
Soils with excessive Leeching and High ph soils and or water.Soils that are potassium fixated. An excess of kitchen salts (sodium) in the root system/enviroment.


Soil

Potassium gets locked out of soil growing at ph levels of 4.0-5.5
Potassium is absorbed best in soil at a ph level of 6.0-9.5. (Wouldn’t recommend having a ph of over 7.0 in soil) anything out of the ranges listed will contribute to a Potassium deficiency.


Hydro and Soil less Mediums

Potassium gets locked out of Hydro and Soil less Mediums at ph levels of 4.0-4.5, 6.0-6.5.
Potassium is absorbed best in Hydro and Soil less Mediums at ph levels of 4.7-5.3, 6.7-8.5. (Wouldn’t recommend having a ph over 6.5 in hydro and soil less mediums.) Best range for hydro and soil less mediums is 5.0 to 6.0. Anything out of the ranges listed will contribute to a potassium deficiency.



Solution to fixing a Potassium deficiency
Any Chemical/Organic nutrients that have potassium in them will fix a potassium deficiency. Again Peters All Purpose plant food 20-20-20, will cure the potassium deficiency , Miracle grow Tomato plant food, Miracle grow All purpose plant food.( Only mixing at ½ strength when using chemical nutrients, or it will cause nutrient burn!) Some other supplements of potassium are: Wood ashes, which are fast absorption, Kelp Meal, which is medium absorption, Greensand, which is slow absorption, granite dust, which is slow absorption. Sulfate of Potash, Sulfate of Potash Magnesia, Muriate of Potash, which are medium absorption. FOXFARM GROW BIG HYDROPONIC CONCENTRATE, which is fast absorption. (FFGB can bring your ph down as well) Earth Juice Meta-K, which is fast acting. (Can bring down your ph as well) Leaves will never recover, but the plant will show recovery after about 4 to 5 days when using a fast acting nutrient.

The problem of "TO MUCH P" is encountered WAY to much in growing cannabis. This happens with the use of high P "Bloom" nutrients. Usually by the application of them in to high concentrations and to early use application.
MANY synthetic nutrient makers tell you to use their "bloom" products in very "aggressive" amounts and others simply have you believe that adding stupidly high amounts gives you better faster yields and finish's.
WRONG! Unless you have good specific long term experience with the use of high P bloom feeding you will have problems supplementing with them. The knowledge of NPK ratio's for Cannabis growing at all stages is a way to avoid these problems. Sadly, that is generally a learned by experience gift. Some of us try and help, yet to many new to growing people fall for the nutrient makers wild claims.
More is not better all the time and limits are reached quickly.

I can not say enough that the use of Dyna-Gro "grow" is going to be all you'll need to get what you want at low cost and easy to use, if you are just starting out!

Got a few grows under your belt and ready to move up to something more aggressive?

I would suggest that you KEEP using the Veg formula till the END of the 3rd week of flower and THEN change to a "high P Bloom" nutrient. "Spike" the P&K at week 6 and don't keep pounding it, just use it 1 or 2 times and that's it (the "spike"). You should be able to begin to zero in on what works best for you from there.

High P nutrients like MG, Peters, Some FF powders and any thing with P ratio's over 9 should be avoided unless that's your "spike" and use it only once!

Keep them green and happy......You will be too!

Hey Dr. Who...... Zander was talking about Potassium not Phosphorus I know they both start with P so it's ok
And.... i would agree with Zander's statement as well I use a soluble kelp solution once a week or so as a Potassium\micro nutrient boost. Great for all stages of growth...
happy growing

mmmmbrownies said:

Hey Dr. Who...... Zander was talking about Potassium not Phosphorus I know they both start with P so it's ok
And.... i would agree with Zander's statement as well I use a soluble kelp solution once a week or so as a Potassium\micro nutrient boost. Great for all stages of growth...
happy growing

Click to expand...

i love the kelp. and thanks for correcting people on the P lol

Good read/info

mmmmbrownies said:

Hey Dr. Who...... Zander was talking about Potassium not Phosphorus I know they both start with P so it's ok
And.... i would agree with Zander's statement as well I use a soluble kelp solution once a week or so as a Potassium\micro nutrient boost. Great for all stages of growth...
happy growing

Click to expand...

Correct a mundo! (but I just HAD to make my point) LOL,,,,guess I shouldn't bong up before post'in eh!!!!

K (potassium) is much more easy to control and does really fun stuff if you now how to use it.
Enhances coloring of the plant and helps the flowering onset......DAMN I'm gassed!!!!

Thanks dude and that's a REAL good catch!!!!

nice to see everyone getting on lol. am going to be using chicken shit for my P-K boost. now anyone no how i should us it. am going to the farm to get some old shit not new shit. i was told to put it in a bucket for say 30sec then wait till the water goes a bit milky then take it out. then use it with a feed? EH?!! how much to us? this is a new one to me

Cool temps can cause a plant to look like it has P problems.

GrowerGoneWild said:

Cool temps can cause a plant to look like it has P problems.

Click to expand...

yeah this is true (grower) i happend to me took about 1h to find out why it was like that my temp was at 16 over night and 20 when lights on so there was my issue

I remember sub-cool saying chicken manure wasn't good for soil mixes, it was years ago, so I am not going to try and dig it up. I never used it before, just remember reading about it.

Do potassium silicate products like Rhino Skin or Silica Blast just deliver potassium quicker like an espresso shot or what's the difference in this type of potassium and any other 'K' in fertz?

"
Horticulture
In horticulture, potassium silicate is used as a soluble source of potassium and makes also the growing medium more alkaline.
" - Wikipedia

So Great news 7 of the Strawberry Ice are out in under the 400w and looking good. unfortunately out of 20 Amnesia Trance NONE have poped at all, there is one seeds that i will post with the new upto date pic's, that we do not know if it Ice Rhino Trance, i am hoping its the trance just so i can clone the crap out it lol. So keep posted for more pic's

https://www.rollitup.org/t/grow-for-broke.838380

I think (K) Potassium problems are quite a common occurrence indoors using synthetics nutrients. Seems to be alot of people on this forum with similar issues.

Important not to go heavy on all the calcium in the products as too much calcium antagonizes potassium uptake as well as ammonia nitrogen which is in many base products and additives including cal mag supplements.

Over feeding and not flushing out your containers with mild strength nutrient solution every couple weeks can put your rhizosphere out of wack and lock out (k) uptake causing the yellow/brown rusty edges which work its way from bottom of plant up until you got bigger issues like flower site die off (turns grey shrivels weaker smaller flower sites and they die). This is potassium deficiency in a nut shell.

Trying to just add potassium isnt going to fix the issue just make shit worse. You really want to figure out whats causing the problem. Most likely calcium and nitrogen excess that lead to salinity problem at the roots. This usually goes hand in hand with incorrect Ph since the water and salts in medium become acidic and potassium is best absorbed on the higher end of the Ph range 6.2-6.3 in soilless. While nitrogen is best absorbed in the 5.8-6.0 range.

Flush your medium with 1/4 strength nutrients to help break down the nutrients at the roots and dont flush all at once, give a good rinse wait a few minutes than apply more, continue this for half hour or so until they are rinsed heavily checking the run off between waterings make sure its going down (ppm's). Once its in an acceptible range you can wait until containers are nice and dry and resume 1/2 strength of base nutrients and work your way back up to full strength. And do not over use calcium additives they can wreak havoc on your plants. Calcium is important but too much of anything is never good.

Regarding the use of "pk boosters and additives" its not how its when. You dont need to overdue these products they are meant to be used at specific times during flowering much like Tea Spikes and top dresses are used in organics to give that extra push to your plants when they need it. PK boosters should be used at the onset of flowering for a feeding or two and than not resumed until week 6/7 at end of flowering for a week or a so couple feedings and not much more than that. Hope this helps.