WOW! What a bunch of crap info (for the most part)!
1: He's using an organic feed....That means NO nutrient SALTS! DON'T flush,,,flushing is for toilets!
2: He's feeding at 2.5 times the required amount. Can you SEE the P problem??? TOO MUCH!
2A: NO amount of added "N" will fix that......You DON'T need "more" N.
3: pH all ingoing fluids to 6.5 and FORGET about the soil pH!!!!
A pH meter is always good to have. pH all ingoing to your target 6.5.....
TDS/EC pen is so unneeded for soil grows of any kind (Yeah, that includes coco grows)!
A Ca/Mg supplement should ALWAYS be added to RO and Distilled water! No mater HOW you grow.
A simple AACT tea or an over the counter equivalent (a "tea" or "zyme" product) will ensure proper "living" microbial counts in your soil, if you feel you need to amend them.
I suggest the use of an organic kelp to help your overall plant health. The added B vits and Humic/Fulvic acids will go a long way to a better result. Fulvic acids help REGULATE P uptake,,,use from the start next time.
Now then, simply pHed water for 5-7 days and return to feeding the PROPER amounts of your nutrients.
It will take around 7-10 days for the P tox to stabilize. The yellowing will slow way down and almost stop (some yellowing is normal in later bloom stages).
P tox is the MOST common problem around here in bloom!
You'll learn, so don't fret about it.
You said your growing auto's?
Organic and in soil is the best thing for those! Light feeding as they tend to be "fussy" feeders helps too.
P problems for auto's is common and easy to do if not familiar with them.
Grow on
Doc
I disagree on PH. If you knew anything about organics you would know that PH of your water/solution DOES NOT MATTER. People messing with PH screws up more grows than anything else. You do realize that most PH down is phosphoric acid. Did you know that Botanicare's PH down actually list the NPK at 0 15 0? That's a shit ton of P. How many growers even consider this? Even when using mineral salts the alkalinity of your water is more important than the actual PH so long as your growing in PH buffered medium. If your alkalinity is below 100ppm PH adjustments of your water/solution are not necessary and can actually be harmful.
Water Quality: pH and Alkalinity
Recently, some growers have expressed concern about the "high pH" of their irrigation water and its potential adverse effects on plants. The purpose of this article is to allay some of these concerns by pointing out the difference between "high pH" and "high alkalinity".
Alkalinity and pH are two important factors in determining the suitability of water for irrigating plants.
pH is a measure of the concentration of hydrogen ions (H+) in water or other liquids. In general, water for irrigation should have a pH b etween 5.0 and 7.0. Water with pH below 7.0 is termed "acidic" and water with pH above 7.0 is termed "basic"; pH 7.0 is "neutral". Sometimes the term "alkaline" is used instead of "basic" and often "alkaline" is confused with "alkalinity".
Alkalinity is a measure of the water's ability to neutralize acidity. An alkalinity test measures the level of bicarbonates, carbonates, and hydroxides in water and test results are generally expressed as "ppm of calcium carbonate (CaCO3)". The desirable range f or irrigation water is 0 to 100 ppm calcium carbonate. Levels between 30 and 60 ppm are considered optimum for most plants.
Irrigation water tests should always include
both pH and alkalinity tests.
A pH test by itself is not an indication of alkalinity. Water with high alkalinity (i.e., high levels of bicarbonates or carbonates) always has a pH value ÷7 or above, but water with high pH doesn't always have high alkalinity. This is important because high alkalinity exerts the most significant effects on growing medium fertility and plant nutrition.
Acidification of High Alkalinity Water
Many greenhouse operators inject acid (e.g., phosphoric, nitric, or sulfuric acid) into water with problematic high levels of alkalinity.
Acidification of water having high pH but low alkalinity is rarely necessary. The use of acid injection sh ould be considered very carefully for several reasons. First, it is an extra step in production which will require additional materials and equipment. Second, acids are dangerous to handle and may damage some injectors and piping systems. Third, phosphoric or nitric acid are sources of P and NO3, so the regular fertilizer program may need to be modified to take into account the addition of these nutrients. This would depend on how much acid must be used to neutralize the alkalinity and reduce pH. Fourth, sometimes acid injection causes the solubilization of normally precipitated (unavailable) forms of trace elements resulting in levels toxic to plants.
The amount of acid required to reach the desired pH (i.e., neutralize alkalinity) is determined by laboratory titration of a water sample with the appropriate acid or by a calculation procedure. Some "fine-tuning" may be needed later when actual inject ion is started. Acid is always injected prior to the addition of fertilizer or other chemicals.
Prepared by Douglas Cox
Plant and Soil Sciences
University of Massachusetts
Amherst
August 1995.
And as they say the proofs in the pudding. These are clones in Promix HP. Have never adjusted my PH and they seem to be doing just fine. My waters alkalinity is around 65ppm.
Pic 3 was taken the day they were transplanted. Pic 14 3 days later.
That being said your dead on about P overload. It kills a bunch of grows.