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- #641
Thanks buddy; I think flushing and testing my runoff with my new pH meter I am going to get there!
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Thanks buddy; I think flushing and testing my runoff with my new pH meter I am going to get there!
Yup, but listen to the pros if you are really concerned. It takes time and patience. You can always make sure you have a better medium next time(mix) then you have less worries about pH.
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- #643
Thanks for the post Shed and information from Cornell. Actually I pretty much have made a slurry so that should tell me the story of my soil. I will post the results tomorrow.
I have read many times that testing runoff pH isn’t valid and since you say it’s complicated and a slurry test is best can you explain why the runoff pH does not represent what the pH of the water in the soil actually is? It just makes sense to me that what the runoff is, also is what the plant is really experiencing more so than what the water you add is but as usual I could be totally wrong?
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- #644
I am actually enjoying solving the mystery of my pH problem so I have patience I just want to get my plant healthy and getting fatter!!
I bought another big bad of coco when I was at the store buying my pH meter so I am committed for a while. 
I don't know much about coco and what gets mixed with it (actually thought it was used alone) but with FFOF or similar stuff the pH is pretty neutral so you're just pHing your water. Shed or Penny can probably state it better.
I'm home now so I'll post the instructions from Cornell, but every test you do requires distilled water.
Soil does buffer pH best but weather it rises or falls depends on the alkalinity of your water.
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- #647
Thanks, Shed but you did post the Cornell instructions already unless you are referring to others?
Have been reading about alkalinity, very interesting. Thanks for the info.
No, sorry. The Cornell instructions were on how to run pass-through pH testing, which involves soaking the medium, waiting an hour, and then adding distilled water. It was much more complicated if less messy than the slurry test!
I've had an ongoing email conversation with an expert at ProMix for the last week. The upshot upends most of what we do so I'm trying to ignore his advice because it's easier! At some point I will summarize it and post it in my thread later this week. I'll @ you when I do.
I've had an ongoing email conversation with an expert at ProMix for the last week. The upshot upends most of what we do so I'm trying to ignore his advice because it's easier! At some point I will summarize it and post it in my thread later this week. I'll @ you when I do.
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- #649
Cool, I look forward to your post because I am considering switching to Promix because it is about 1/4 the price of the coco mix I am currently using. Should be an interesting read with the expert upending most of what we do!!
I still have some clarifying questions for him but he's already made his case!
For what it's worth, here is the Cornell Pour Thru method:
Steps for the PourThru method:
1. water containers to saturation (so that a few drops of water come out of the bottom of the container) with the normal irrigation water they have been receiving
2. after container has drained for one hour, place a saucer under the container
3. pour enough distilled (DI) water on the surface of the container to get 50 mL (1.5 fluid ounces) of leachate to come out of the bottom of the container (Table 1)
4. collect leachate for pH and EC testing
5. calibrate pH and EC meters
6. measure pH and EC of samples
See table 1
INTERPRETING TEST DATA
EC (Electrical Conductivity)
The values that you measure for EC will depend on the method you use for testing the container media. EC guidelines for several horticulture crops are presented in the table on page 8.
Problems with Low EC
A low EC means that your plants are not getting enough fertilizer salts. Symptoms can include stunted plant growth or leaf discoloration due to lack of nutrients. Nitrogen deficiency (yellowing of lower leaves) often appears first.
Problems with High EC
Excess salts can accumulate when: you are applying more fertilizer than the plant requires; the container media has a high initial salt level; leaching during irrigation is insufficient; or your water source contains naturally high levels of salts (bicarbonates,calcium, chloride, magnesium, sodium, or sulfates). Excess salts can cause tissue death. Symptoms often appear first on the lower leaves and appear as yellowing (chlorosis) or browning (necrosis) that begins at the edges of the leaves and spreads inward. High salts can cause root tips to die back; and plants may show wilting even though the medium is still moist. High salt levels have been shown to increase the incidence of Pythium root rot.
pH
pH affects the ability of nutrients to dissolve in water (solubility). Solubility is important because roots can only take up nutrients that are dissolved in solution and cannot take up the solid form of the nutrient. The graphs on page 5 show nutrient solubility in container media (left) and of soil (right) in relationship to pH.
Problems with Low pH
In container media, the micronutrients iron, manganese, zinc, and boron are highly soluble at low pH (pH 5.0-6.0). Therefore, at low pH these nutrients are available and readily taken up by roots. If pH is too low, typically below 5.0 for most plants, the nutrients become so soluble that they may be taken up at harmful or toxic concentrations. A classic symptom of this is iron toxicity which appears as leaf bronzing and chlorosis which appear first on lower leaves. Certain plants that are especially efficient at taking up iron, such as seed and zonal geraniums and marigolds, can exhibit iron toxicity when pH is below 6.0.
Problems with High pH
At high media pH the low solubility of phosphorus, iron, manganese, zinc, and boron makes these nutrients less available to be taken up by roots and so deficiency symptoms can occur. Certain plants are less efficient at absorbing micronutrients (especially iron and manganese). These plants require a slightly lower pH to be able to absorb enough of these nutrients. A classic example of this is iron deficiency is petunia. Affected plants show yellowing between the veins on the upper leaves. Often there is enough iron provided in the fertilizer/container media, but the pH is too high for roots to absorb it.
LONG-TERM MONITORING
Sampling container media for pH and EC is most effective when samples are taken periodically during crop production as opposed to measuring at only 1 time point. This allows you to look for trends. If pH or EC begin to creep outside of the preferred range, then action can be taken to bring these under control. In the example below, bedding plants were grown with a complete fertilizer mix (21-5-20 N:K2O 2O5) at 3 different levels of nitrogen.
For what it's worth, here is the Cornell Pour Thru method:
Steps for the PourThru method:
1. water containers to saturation (so that a few drops of water come out of the bottom of the container) with the normal irrigation water they have been receiving
2. after container has drained for one hour, place a saucer under the container
3. pour enough distilled (DI) water on the surface of the container to get 50 mL (1.5 fluid ounces) of leachate to come out of the bottom of the container (Table 1)
4. collect leachate for pH and EC testing
5. calibrate pH and EC meters
6. measure pH and EC of samples
See table 1
INTERPRETING TEST DATA
EC (Electrical Conductivity)
The values that you measure for EC will depend on the method you use for testing the container media. EC guidelines for several horticulture crops are presented in the table on page 8.
Problems with Low EC
A low EC means that your plants are not getting enough fertilizer salts. Symptoms can include stunted plant growth or leaf discoloration due to lack of nutrients. Nitrogen deficiency (yellowing of lower leaves) often appears first.
Problems with High EC
Excess salts can accumulate when: you are applying more fertilizer than the plant requires; the container media has a high initial salt level; leaching during irrigation is insufficient; or your water source contains naturally high levels of salts (bicarbonates,calcium, chloride, magnesium, sodium, or sulfates). Excess salts can cause tissue death. Symptoms often appear first on the lower leaves and appear as yellowing (chlorosis) or browning (necrosis) that begins at the edges of the leaves and spreads inward. High salts can cause root tips to die back; and plants may show wilting even though the medium is still moist. High salt levels have been shown to increase the incidence of Pythium root rot.
pH
pH affects the ability of nutrients to dissolve in water (solubility). Solubility is important because roots can only take up nutrients that are dissolved in solution and cannot take up the solid form of the nutrient. The graphs on page 5 show nutrient solubility in container media (left) and of soil (right) in relationship to pH.
Problems with Low pH
In container media, the micronutrients iron, manganese, zinc, and boron are highly soluble at low pH (pH 5.0-6.0). Therefore, at low pH these nutrients are available and readily taken up by roots. If pH is too low, typically below 5.0 for most plants, the nutrients become so soluble that they may be taken up at harmful or toxic concentrations. A classic symptom of this is iron toxicity which appears as leaf bronzing and chlorosis which appear first on lower leaves. Certain plants that are especially efficient at taking up iron, such as seed and zonal geraniums and marigolds, can exhibit iron toxicity when pH is below 6.0.
Problems with High pH
At high media pH the low solubility of phosphorus, iron, manganese, zinc, and boron makes these nutrients less available to be taken up by roots and so deficiency symptoms can occur. Certain plants are less efficient at absorbing micronutrients (especially iron and manganese). These plants require a slightly lower pH to be able to absorb enough of these nutrients. A classic example of this is iron deficiency is petunia. Affected plants show yellowing between the veins on the upper leaves. Often there is enough iron provided in the fertilizer/container media, but the pH is too high for roots to absorb it.
LONG-TERM MONITORING
Sampling container media for pH and EC is most effective when samples are taken periodically during crop production as opposed to measuring at only 1 time point. This allows you to look for trends. If pH or EC begin to creep outside of the preferred range, then action can be taken to bring these under control. In the example below, bedding plants were grown with a complete fertilizer mix (21-5-20 N:K2O 2O5) at 3 different levels of nitrogen.
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- #651
I look forward to hearing about his case; sounds very interesting.
I had a pretty busy day with my flushing but I still managed to read your Cornell method and that is pretty much the method I used but I didn’t use distilled water to make the leachate flow instead I just used more of the normal irrigation water. I don’t know if that makes a big difference but I did test my slurry this morning that I let sit overnight and it was the exact pH at 6.1 in the morning as it was in the evening so it doesn’t look like my coco mixture is the culprit which is a relief.
I did the method you advised flushing with 6.3 pH water until my leachate was the same pH and it took counting the last one with nutes nine gallons so there was a lot of I assumed built-up ions in the soil. Hopefully now that will straighten out my worse plant but now I still have to do all the others in the coming days. Here she is in the tub waiting to be flushed.
Really happy with that plant though because it is a great budder despite all the pH and brown leaf problems; I would estimate I may get five ounces from her. Hopefully the next generation of cuttings will fare a lot better. Anyway thanks for the advice Mr Shed!!!
Just make sure the last gallon is nutes!
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- #653
Yes sir, the last gallon was nutes!!!
Shed has given you a ton of great advice the last couple pages so keep following what he is saying. I’m along for the ride now and can’t wait to see how those quadlines turn out. One really important thing I’ll reiterate that Shed said is to get something softer then bailing wire for training. The wire will cut into the plant and cause some problems as the plant keeps getting larger. Good luck and I’ll be lurking in the background watching those quads!
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- #656
Hey, Asesino…. Glad you stopped by. Here is a pic of one of my quadlines; let me know your expert opinion. So far the method is working out pretty good but on my other plant I have had a few broken branches. D‘oh!!
Yes, Shed has given me some great advice along with lots of other people which I am very grateful for so I really try not to be a contrarian but this insistence that I use a softer wire has me perplexed because everyone seems to agree but I don’t really see why. If I could just drive to a store I would get some and in fact today I was out and I went to two big-box hardware stores and there was nothing available in the horticulture departments.
The only thing they had was house wiring and that stuff is about a dollar a foot plus the insulation has to be stripped and the bare ground wire is useless. And as I said in a previous post I am monitoring my plants and the wire does not seem to be causing any damage besides people supercrop their branches by squeezing and bending the plants and that doesn’t seem to hurt them so why is wire seen as being so damaging. I’m not being difficult and if I could find some stuff locally I would buy it but I don’t see the point of going to the expense and trouble of getting house wiring to replace something that seems to be doing just fine. To me, it seems like the old wait an hour before you go swimming or you’ll get cramps kind of thinking but does anyone know anyone who got cramps from swimming after eating?? Can anybody show me a thread where somebody used bare wire and had catastrophic results? I’m really not being argumentative I just don’t understand why everyone is so adamant about this when it’s not hurting my plants so far. I have been trying to think of something I could put on the end of my bailing wire like maybe some duct tape to soften it.
And I have to give credit to @TriangleCheese because I tried his back building method by topping half my buds and it looks like it made a significant difference in bud size. These two pictures are on my two main top branches from my plant that I topped so theoretically they should be the same size but the bud that was topped definitely is significantly more full.
I use all three wires, and the bare one adds a bit of copper to the grow! But I didn't buy it for that purpose, it was just sitting around.
From what I've read (and I think even Light Addict confirmed this though I could be mistaken), you get fatter more bag-ready buds from back building, but you prevent further growth north. This doesn't increase the total harvest weight in the end.
This is just from what I've read from those who have tried it. I like long foxtailed colas so I never snip them. Imagine what the one on the right would have looked like if I had topped it when the backbuilders recommend:
Back building was a technique used by one of LA’s old buddies who owned a liscenced grow in Cali. It causes all the buds to turn out more uniform in size and shape increasing bag appeal.
I gots no bag appeal...but I've got colas as long as my forearm!
ia There any other reason to do this technique other than bag appeal?
Density?
Quality?
Density?
Quality?