Hello everyone,
I finished reading this thread shortly after my last post, but the research has continued on in other places.
@Capulator - I noticed at some point in time you had moved away from Peters/Jacks, and began formulating your own solutions with salts. I also noticed that you had returned to Jacks/Peters after a couple of runs that did not match the performance. I bring this up for two reasons; I have information(an email) that may be relevant, and I would also like to hear more about your experience and what noticeable differences in crop performance you were able to identify.
Following is an e-mail from a local agricultural supply company, I was speaking directly with the two members of their team members responsible for creating custom nutrient solutions:
"You are right in the nutrient guarantees of various companies formulating fertilizer's. By state standards we need to register a fertilizer if it is being openly marketed to more than one individual. With that the NPK values are as you noted on the common store bought fertilizers.
If you market the blend with seaweed or various micronutrients then they have to be claimed on the label, however a company can add various components and if carefully done mention these in their marketing material, and not list on the label. This is done all of the time.
We can also formulate a custom blend specifically for an individual grower and not make any claims on the label.
The state also requires minimum guarantees of certain nutrients if claimed. For example Magnesium needs a minimum guarantee of 0.5% to be listed, the same rules apply to all of the macro and micro nutrients in the blend. However, we can still add these and not claim them.
We do use a variety of items in our blends such as seaweed, phosphorus acid, worm casting extract and others for various results needed at the particular time for the stage of the plant and not list them."
Perhaps this was already common knowledge, but I thought it was worth noting; the companies can include quite a bit without full label disclosure.
I have been accumulating quite a bit of information through my research and networking, I will be posting some more in the future.
Thank you again for your time and knowledge.
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@NapalmD - Are you familiar with the elemental ratios of your irrigation water for each week of the fruiting stage? I haven't bothered to run the schedules you are talking about through the calculators.
I believe Cap will have information you are looking for, but here's what I can offer:
For two years I've been operating a 2500 sq. foot perpetual flower canopy. The environmental parameters were 400 PPM Co2, 10-25 gallon pots, 85dF, 55-60% RH, 2-3 feedings per day, 3-5 month vegetative stage(5'x5'x10' plants).
A perlite mix doesn't hurt anything at all, but if you time your irrigation cycles and manage your root zone properly, pure coco does the trick everytime-it has for me.
On my 8 week strains, I run the same elemental ratio for the first 5-1/2 to 6 weeks of flower, and then I transition to a low nitrogen bulking feed for 10-12 days, and flush with pH'd water for two or three days.
Week 1 - 6 : 37N-40P-50k-36Ca-25mg-17Su-5Sil (300-350PPM / 5.8 pH)
Day 40/45 - 57 : 10N-115P-150K-17mg-23Su-2.5Sil (300-350PPM / 5.7 pH)
Day 57 - Harvest : Plain water flush (pH 5.8)
Of 23 strains, only one has shown a significant desire for more or less of any element(our Girl Scout a cookies cut is the hungriest plant I've ever seen).
I've recently been experimenting with a couple different ratios for weeks 1-6:
21N-19P-36K-13.5ca-19mg-17Su-5sil(300-350PPM / 5.8 pH) ~ Seeing some general defficiencies across various cultivars with this ratio.
101N-68P-131K-50Ca-55Mg-17S-0.76Fe-5sil(650-670PPM) ~ I'm actually running this on 4 plants flowering plants in the 3-5 week fruiting stage; two different versions of Cookies(indica dominants; tend to be heavier feeders IMO), right next to two identical groups being fed my two other formulas. This appears to be the healthiest set in both cases.
1.All of my ratios are achieved using a variety of "cannabis" nutrients, but I dominantly use the canna line, this means that although the elemental ratios are provided it does not account for the varying levels of potential additives that are not included on the company's labeling; botanical extracts, auxins, PGR, humus, etc.
2. PPM calculated on a x500 scale.
There are studies suggesting that as Phosphorous PPM rise, most microbial/bacterial activity and/or presence is reduced or inhibited, but I've never had an issue running over the 40-50PPM threshold. I can't recall if the source of phosphorous was mentioned in these studies, but that's a potentially critical variable when discussing the efficacy and concentration of phosphorous. There may even be an argument that what's good for a specific cultivar may not be good for the microbes/bacterias, and perhaps hydroponic nutrient companies purposefully provide higher phosphorous solutions to encourage a sterile root area for customers using inert mediums.
I imagine you may be wondering what relevance all of this information I've provided has to your post; its about that 7-10 day flush, your drop in bloom booster 2 weeks from chop, and potential swing in osmotic pressure at the root zone.
I would suggest that if you are dropping the nitrogen PPM significantly(essentially only allowing what is necessary to be present) in the final 10-14 days of a plants life, you do not need to run such a large flush or cut back on the bloom booster unless the plants are showing signs of overfertilization(burnt tips or lockouts created by specific elemental over-concentration). Also, many don't realize that the root zone responds too a lot of variables in different ways, well beyond the commonly understood overwatering, under watering, overfertilization, under fertilization, temperature fluctuation, there is also osmotic pressure fluctuation; a sudden drop or increase in EC/PPM can be stressful to the roots and will affect it's uptake in some manner.
Finally: I've never flushed more than 4 days, and if I ever felt the need to flush for more than three days in coco to achieve a great smoke, I assume that the cultivar in question was over fed in some fashion.
Edit: In terms of varying calcium and general element sources, I believe that a variety is not harmful. As you continue to use different source, you will find one or two products that perform the best, or good enough for your needs-stick to that one or two. I say this because I believe the purity and size of suspended element is relevant to the plants ability to uptake and use said element in an effecient manner, and because the more you add and have variables in your line up, the more stress you have when something isn't going right.
Regardless of what I say, there are thousands of different ratios and techniques that work; find something that you enjoy!
Cheers!
X
(Foxtail ing was due to heat)
