The myth, of the high P myth?

[YosemiteSam]

7 weeks into flower

7 weeks into flower







It is now pretty obvious I underfed these a little. Rookie mistake, I got fixated on a freakin number when I should have been looking at and paying more attention to the plants themselves.

It's not bad...but it could have been better. One step closer to actually figuring out what I am doing.

 

[YosemiteSam]

Here is one that shows the underfeeding. Should be at least one more week before this much yellowing occurs. Plus they are going yellow pretty quickly...the good news is very little flush will be required.

 

[Carboy]

Here is one that shows the underfeeding. Should be at least one more week before this much yellowing occurs. Plus they are going yellow pretty quickly...the good news is very little flush will be required.

One particular element or too low total on the PPMs?

 

[YosemiteSam]

That is what I am not sure of. I only fed above an EC of 1.5 three times...at like 1.8. I am not seeing what you would normally call a deficiency of one element (with the possible exception of one plant) so I suspect it is just an overall underfed condition.

I plan to use very similar ratios and just up the EC on the next grow. In fact I am jacking up the EC of the plants in veg a little at a time to prepare them for harder feeding.

Anyways...still a good grow and the great news is that there is still room for improvement. I will also be adding the Ag-Sil silica to the next grow. Me head is debating itself on the fulvic at the moment...that outcome remains unknown at this point.

 

[spurr]

YS,

where are you getting the Ag-sil from?

 

[YosemiteSam]

Custom Hydro. I am not sure if I am getting a sample or if they are carrying it already...but they plan to.

edit...just checked the site. It is listed.

 

[analogue]

Custom Hydro. I am not sure if I am getting a sample or if they are carrying it already...but they plan to.

edit...just checked the site. It is listed.

I'm using the Ag-Sil from CHN @ .2 grams per gallon.

 

[Carboy]

That is what I am not sure of. I only fed above an EC of 1.5 three times...at like 1.8. I am not seeing what you would normally call a deficiency of one element (with the possible exception of one plant) so I suspect it is just an overall underfed condition.

I plan to use very similar ratios and just up the EC on the next grow. In fact I am jacking up the EC of the plants in veg a little at a time to prepare them for harder feeding.

Anyways...still a good grow and the great news is that there is still room for improvement. I will also be adding the Ag-Sil silica to the next grow. Me head is debating itself on the fulvic at the moment...that outcome remains unknown at this point.

It's hard to tell from pictures. I had some looked like yours but in the end was caused by too HIGH an EC. Different varieties, conditions and all that entails. Still mine can't take over 1.5 to 1.6 max. This was a DTW coco type mix. Really baffled me for alot longer than it should have. Looked like shit rest of the way but results were on par. Following times dropped EC with more frequent feeds --- all was good.

 

[YosemiteSam]

Something else is going on that I don't understand at all yet. It looks like every plant in this grow is going to finish about a week sooner than I have seen in previous grows.

We actually cut a White Russian today, at 7.5 weeks. Trimmer hash confirms it is done...as well as microscope.

Now I kinda wish I was the note taking type...DOH.

 

[libby]

View attachment 102405

Here is one that shows the underfeeding. Should be at least one more week before this much yellowing occurs. Plus they are going yellow pretty quickly...the good news is very little flush will be required.

View attachment 102406

I would of thought that underfeeding would of shown through the whole plant evenly, no?. nice plants .

 

[libby]

 

[PointofNoReturn]

I think the excess P in Flower Products is too produce Osmotic Stress from the Salts in the Rootzone, which pushes the Plant into a even more Generative Stage. I also think that Products like Koolbloom(Ripen) or Shooting Powder use the same Mechanism, just with more complex Sources of P and K to further increase the effect(Tradesecrets lol). P as an Anion is easily leached from the Medium cause its not as soluble, to the Buffers of the Medium and the Roots as well.

My take at Chemistry after reading a few things lol. Obviously i may be wrong with that Assumption.

 

[PointofNoReturn]

I didnt mean to end the Thread. Come on, someone has to disagree.

 

[BasementBreeder]

Point,

I can't imagine osmotic stress is a good thing. Do you have any sources for the claim that it "pushes the Plant into a even more Generative Stage"? Also, why would different sources of P and K matter with respect to increasing this effect?

More than likely, the excess P is there to help balance the pH and/or the manufacturers have no idea what the correct ratio of elements is.

 

[PointofNoReturn]

I didnt claim anything, just wrote my Assumption.

http://www.crophouse.co.nz/files/Gr_P07_-_Steering_balance_by_irrigation_-_view.pdf

http://urbangardenmagazine.com/2010/08/plant-stress/

Maybe a good start on the Subject. If you look at Dry Koolbloom and Shooting Powder, both are supposed to initiate an Extra Flower Cycle( i can attest to Ripen the Euro Version of Koolbloom working in that regard), both have at least 2 extra Sources of P and K, compared to other PK Booster.

 

[BasementBreeder]

I'm aware that certain stresses can be beneficial. Those articles you listed don't mention anything about excess P or osmotic stress though. (On a side note, can you clarify what you mean by 'osmotic stress'? Wouldn't that cause nute burn?)

As for the different sources of P and K, I'm sure they're there to add other elements. The actual source(s) of P (or K or NO3-N or NH4-N or whatever) don't affect uptake afaik.

However, I have read on this forum and others, that upping the P content at certain times during flowering can be beneficial. Unfortunately, I have yet to find any credible sources for this claim (my guess is it comes from the nute makers but I could be wrong).

 

[PointofNoReturn]

Read the Part about EC in the pdf. It doesnt mention the word Osmotic but its right there. Not beeing able to take as much Water because of EC is Osmotic Stress for the Plants.
http://en.wikipedia.org/wiki/Osmotic_shock

Even Horticulture Grade Fertilizers have the High P Content if they are for Heavy Flowering/Fruiting Plants. Plants can do fine with lower Amounts of P in Flowering but it seems the Theory that additional P helps is also widely spread in Horticulture.

Its not that Hydro Store Products dont work(some of them are actually decent and the Technology involved in making them is as Advanced as it is for Horticulture Suppliers),its just that they have special Marketing attached to them, aimed at Stoners who are used to paying lots for Shit.

Eh offtopic

 

[BasementBreeder]

Many fertilizers that are designed for outdoor, non-container use contain high levels of P. This is because the P anion is easily leached from the soil. It also has a tendency to form bonds with Al and Ca, making it insoluble and unavailable to roots. This isn't really a problem for indoor container gardening(although Ca and P still bond indoors. citric acid anyone?)

From the wiki link: "Under conditions of high concentrations of either salts, substrates or any solute in the supernatant, water is drawn out of the cells through osmosis" - this is the cause of nute burn. I have a very had time believing this could be beneficial.

If the P is there simply to create a high EC (and osmotic stress), then why not just up the amounts of all the elements proportionally?

 

[spurr]

Many fertilizers that are designed for outdoor, non-container use contain high levels of P. This is because the P anion is easily leached from the soil. It also has a tendency to form bonds with Al and Ca, making it insoluble and unavailable to roots. This isn't really a problem for indoor container gardening(although Ca and P still bond indoors. citric acid anyone?)

From the wiki link: "Under conditions of high concentrations of either salts, substrates or any solute in the supernatant, water is drawn out of the cells through osmosis" - this is the cause of nute burn. I have a very had time believing this could be beneficial.

If the P is there simply to create a high EC (and osmotic stress), then why not just up the amounts of all the elements proportionally?

It's funny that I was about to write nearly the same thing as you just wrote. I mean very close to the same thing, I was going to make all the same points. But I think you worded it better, nice post

P.S. to help keep phosphate (Pi) anions soluble is the very reason I use citric acid (as well as to lower pH of fertigation water), for its ability to chelate cations/make phosphates soluble from Al-Pi, Fe-Pi, Ca-Pi, etc.

 

[PointofNoReturn]

It's funny that I was about to write nearly the same thing as you just wrote. I mean very close to the same thing, I was going to make all the same points. But I think you worded it better, nice post

P.S. to help keep phosphate (Pi) anions soluble is the very reason I use citric acid, for its ability to chelate cations/make phosphates soluble from Al-Pi, Fe-Pi, Ca-Pi, etc.

Im disappointed.