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Why the Big Ph difference ??

Sixx

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So I prepare my 7 gallons of water in a big ole bucket... Add a big airstone and turn on the pump...Add my 1 part GH FloraNova Bloom at 2 Tsp/Gal., and let it bubble away for hours...Ph down to 6.1-6.2, and leave it over night, and the entire next day. still 6.1-6.2... So I dump all 7 Gallons of water into my clean tote which houses 1 Nirvana Ice from seed at about 35 days into bloom.
An hour later I check the Ph in the tote and its down to 5.1-5.2.

I run 3 pumps in the tote....2 Dual outlet, and 1 single outlet 5 stones in the tote total... I also have 2 5Gal buckets running 2 airstones each, and using the exact same water from the exact same Res... And the Ph in those holds at 5.9-6.1

So whats the deal with the tote at 5.1 ??? Too much air ??
 

Sixx

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Heres a couple pictures of the tote in question... If it helps :)
Tote_Off-750.jpgTote_On-750.jpg
 

v35b

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Why do all that? I grow in a tote too,but I leave one hole unused to siphon the old water out and refill.Then I add the nutes and adjust the PH.
 
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What is happening with your ppms when the pH falls?

It doesn't look like too much air.
 

Sixx

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I dont have a PPM meter.
 
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v35b said:
Why do all that? I grow in a tote too,but I leave one hole unused to siphon the old water out and refill.Then I add the nutes and adjust the PH.
IMO, sixx's routine is the right way to do things. You need to give your nutes time to buffer the water before you pH. I also think it is a good idea to rinse out the totes between nute changes.
 

Hushpuppy

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Was the tote in question fresh and clean from start or has it been in use and had nutrient residue in the bottom? Do the roots hang into the water? I have experienced PH change as nutrients are used from the water(in coco which is good at stripping nutes from the water and holding them within the medium), but that much change within an hour tells me that there is another chemical present in the tote.

You say that you have 2 5gal buckets that run the same water from the same rez. Are you pumping water to them from the tote or are the buckets and tote all getting their water pumped from a separate single rez?
 

Sixx

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Ummm... I used duct tape to keep air hose and stones in place. Could it be the tape ??? Look at the pic with the air turnd off.
 

Hushpuppy

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That's a possibility. It's hard to say what kind of chemical could be leaching out of the tape. I would get something inert like some sizable rocks (quartz wouldn't leach off) to hold the air stones down and remove the tape.

You will have to use a fresh tote though as you will have to wash off the glue residue and that will be tough to get off without solvent that will also have to be removed.
 

Iron Emmett

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Are you getting big water temp shifts?
as your water heats up your PH will drop shouldnt be that huge in an hour but ya never know.
does your meter have a temperature compensator?

Maybe something in your root zone washed off into your water and dropped your ph.
 
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KaptainKush

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Brew yur nutes and then adjust PH.
that does not do much I have left the nutes set and brew for days before and no change in PH Leave them set for an hour and your good
 

pcduck

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I would remove the tape, the roots will hold down your air stone once they reach the rez. I do not run the 1 part I run the 3 part GH and I do my nutes this way.

Aerate for 24 hours, then add nutes, allow this to aerate for another 24 hours. This is especially important step if using city water. This 24 hour time period allows for the buffers in your nutes to counteract with the buffers in your water supply. After this 24 hours of aerating the nutes I check pH and adjust accordingly and allow to aerate once again for 24 hours. Keep repeating this step till I achieve the pH I require.
 

WeedHopper

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pcduck said:
I would remove the tape, the roots will hold down your air stone once they reach the rez. I do not run the 1 part I run the 3 part GH and I do my nutes this way.

Aerate for 24 hours, then add nutes, allow this to aerate for another 24 hours. This is especially important step if using city water. This 24 hour time period allows for the buffers in your nutes to counteract with the buffers in your water supply. After this 24 hours of aerating the nutes I check pH and adjust accordingly and allow to aerate once again for 24 hours. Keep repeating this step till I achieve the pH I require.
:yeahthat:
 

Sixx

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Thanks for all the input peopes.... I have since just reverted back to the 5Gal bucket, The Ph is still dropping , but not as much... Hopefully I can get her back to nuetral.. she has about 2 weeks left... give or take.
 

gchristo

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Sixx,
I was under the impression that a nute solution too strong for your plants would cause a drop in ph, and a too weak nute solution a rise in ph. I couldn't give a good explanation for the chemistry behind this phenom, and someone here will be able to give a better explanation if needed.
Cheers.
 

Growdude

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gchristo said:
Sixx,
I was under the impression that a nute solution too strong for your plants would cause a drop in ph, and a too weak nute solution a rise in ph. I couldn't give a good explanation for the chemistry behind this phenom, and someone here will be able to give a better explanation if needed.
Cheers.
Your correct, dont understand why myself. But when PPM's rise PH falls.
 

Hushpuppy

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I have found that phenomenon as well. I am taking an educated guess here as I am not big on chemistry; but I believe the ph drops when there is a lot of chemicals as it is a more acidic combination of chemicals. Then if the nutes are low initially or the plants quickly take up the nutes, then the acidic chemicals get used up which leaves a higher concentration of hydrogen(found in water) in the solution. Hydrogen causes high alkalinity. If you test pure straight H2O the PH will be pretty high.

I have also found that when there is too little nutes in a given amount of water, it is harder to keep the PH from "bouncing". Once more nutrients are added, the PH seems to settle down more. :)
 

pcduck

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Growdude said:
Your correct, dont understand why myself. But when PPM's rise PH falls.
I always thought this was caused by having more buffers in the nutes then in the water supply. Once the buffers in the nutes overpowers the bufferes in the water the pH drops, because most nutes are low pH for storage reasons. Adding more nutes to do this is adding more ppm,s

If this is happening during a properly nuted and pH rez this was always an indication to me that my plants were drinking the water but not taking up nutes. Just my $0.02
 

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