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Help me lower pH, just got Urea and Blood Meal

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hey guys as the title suggest I am going to try to flush my plants today to lower pH. Here's the situation I have a Alaskan thunderfuck mini-mom and a banana og mini mom in 5 gallon Terra Cotta pots that the leaves are turning yellow. I believe the pH is too high (around 7.4 is my guess).
Yesterday I flushed a blueberry clone in a small 5" pot, but I only had lemon juice and apple cider vinegar to lower pH, it took almost 8 liters of water to flush a pot that could hold maybe 1-1.5 liters. What the fuck did I do wrong? I don't have that much Dechlorinated water to flush the big pots, so I want to do this right.

I only have about 8 gallons of water to flush with today.
here's what I have at my disposal:
MG Blood meal (12-0-0) 3 pounds
Urea (46-0-0) 4 pounds
Apple Cider Vinegar 16 Oz
I also bought 1.5 lbs of Lime, but I'll save that for once I get the pH settled.
So how do I do this? The plants are in the same soil as the blueberry was but I will have to lower the pH much more drastically than the blueberry, as I don't have enough water to run it through nearly as many times.
I believe the pH is 7.4 and I believe there is a strong natural buffer in the soil somehow.

Basically Ive never done this before and could use a little step by step advice, or at least someone to point me in the general direction.




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use corn cobs!:smoking:



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ya right on man. anybody else? Is blood meal more readily absorbed by the roots than urea?
I'm still now sure how to do this properly. I kept flushing low pH water with apple cider vinegar (as low as 3.3) through the pots until the runoff read around 6.5, then I rinsed them one last time with 50/50 RO water/tap water with a few drops of ACV to get the waters pH down to 6.5 to match the soil.
I finished 2 plants this way, will wait for proper pH down, I'm afraid using so much vinegar will kill them

Edited by iyland, 07 May 2010 - 03:37 AM.




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Edited by jcj77d, 08 May 2010 - 01:07 AM.



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too much lemon juice, maybe, but ACV is all natural & organic (if u are using real organic ACV, not just vinegar), & shouldnt cause any probs, & when u have a high ph, dont try to fix it in 1 setting or 1 day, it might take a few days or whatnot to lower the ph in the correct range, eg: fresh FFOF (fox farm ocean forest) has a low starting ph, around 6, so i water w/ 8.0 (which is what my tap is) for a few waterings & eventually the ph (runoff water) comes out around 6.5-6.8, then i keep my waterings/feedings @ 6.5-6.8 & then the soils ph should stay there as long as u water til u get 20-30% runoff to flush out any unused fert salts.

wow, 46-0-0, i wouldnt use, b/c thats just too much N imo, & the blood meal can be done either way as a top dressing, or a water feed, just try to follow the directions, but be careful blood meal can burn plants easy.

whats your starting water ph, tap or other source?, b/c ACV isnt real strong, & can take alot to get it down to 6.5, if the starting ph is 8 or higher.

& ACV really doesnt have that strong vinegar smell, only a slight vinegar smell.
& if your water source is RO water, it should only take a few ml/cc of ACV to lower its ph (7) to 6.5, b/c RO water has no/little buffers in it to make it stable, & chemical ph down will be more harmful to the plants than ACV, b/c its Phosphoric acid.

wikipedia "urea" & "ph down", & "apple cider vinegar"

you have to give the soil a chance to absorb & hold the ACV, your just flushing it all out, thats why its not changing, or hard to change, thats why i said to do your ph'ing over a few days.

okay all good to know in the future, I believe it is real ACV, it is diluted to 5% acidity though, but isn't all vinegar you can buy in a store?
When you say lower the pH over a few days do you mean water them every day? if so how much water? I still have one plant that I watered fully yesterday with pH 5.5 water but the runoff was still 7.5. I did not continue trying to lower the pH, I figured I'd wait and get some advice.

My RO water is 7/0 and yeah it lowers very easily
my tap water is 8.0 and has some conjugates but still lowers fairly easy.
thanks for all the help

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