help!! PH dropping possible nutrient lockout

D

Drunkengrower

Member

• May 7, 2010

• #1

hello, the last few times i have flowered i have noticed that about the 4 week into it my ph levels start dropping instead of rising. is this normal? anyone else have this problem? i am using GH nutes in a ebb and gro system. this always happens aroung the same time and its really starting to bother me. any assistance would be appreciated!!!

 

bombadil.360

Andinismo Hierbatero

Veteran

• May 9, 2010

• #2

hello man, I have no experience with hydro, but if you notice it starts to lower always at that particular time, why not add pH up when you start to notice?

can one add lime to a hydro system?

good luck!

 

F

FLoJo

Member

• May 11, 2010

• #3

have you noticed any root rot? usually that is a good indicator

 

SumDumGuy

"easy growing type"

Veteran

• May 11, 2010

• #4

I've read in many places that pH and TDS play a synchronous role. Have your TDS readings change as well during the same time. Does it go down with pH?

 

jammie

ganjatologist

Veteran

• May 11, 2010

• #5

hey there dg- lots of things cause or contribute to ph shift. some nutrients have worse buffers in them than others. if your running beneficial bacteria in your system and ya use something with sugar/carb in it that can cause a bacterial overgrowth which will drop ph. root rot will cause it. but then as Sum said it could just be normal feeding (see attachment) . how much of a swing are we talkin? are your plants green and growing? does the roots look or smell bad?

 

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C

CloakNDagger

Member

• May 11, 2010

• #6

Yeah, let's see some numbers. What's your pH range? how big is the pH drop?

How are your temps? If they are hot and drinking more water than nutes, then the left over nutes will lower the pH (higher PPM too).

If that's the case, just add plain water back. As long as you are in an acceptable pH range and the plants look well, you should be fine.

I always thought, and in my experience with root rot, the pH always goes up...haven't had to deal with that in a while though so i may be cloudy on that issue.

peace!
CnD

 

M

*mistress*

Member

Veteran

• May 11, 2010

• #7

nitrate nitrogen of fertilizers makes ph rise, over several days/weeks... depends on size of rez & initial starting ph... ammonium nitrogen slightly lowers ph...

if start @ 5.0-5.5, seems to get to 5.7-6.0 & not over, until next change of res/watering...

if start @ 5.7-5.8 (the usual target) the ph may climb over 6.2-6.3, where iron become less available & other micro-nutrients... as posted ^, cec is exchange of ions, as roots absorb nutrients thru osmosis... element goes in, h+ can come out...

slightly acidic solution seems to make media ph rise slower...
checking input solution, ph @ center of container & run-off = :yes...


https://www.icmag.com/ic/showpost.php?p=3132632&postcount=144

 

Last edited: Sep 19, 2010

jammie

ganjatologist

Veteran

• May 12, 2010

• #8

bombadil.360 said:

hello man, I have no experience with hydro, but if you notice it starts to lower always at that particular time, why not add pH up when you start to notice?

can one add lime to a hydro system?

good luck!

Click to expand...

a couple of years back i tried dolomite lime in my 5 gal dwc in an attempt to stabilize ph and add calcium and mag. it didn't work work well because it didn't stay in solution and formed a sediment on bottom of bucket. in hydro, roots require either a charged particle (see my attachment above) or beneficial bacteria or mycos to chelate the organic compounds to be absorbed just like it does in soil- or at least thats my understanding of plant physiology

 

D

Drunkengrower

Member

• Feb 7, 2015

• #9

Shit

 

dominicangreen

Weed Robot

Veteran

• Feb 7, 2015

• #10

Need be more pacific
What is your room temps ?
Are you topping off with notes to reservoir?
Whats does your tds read after each day?
Humidity % day and nights?
Are roots colored brown or look slimy?
Have you flush when you flip to 12/12?
Water temps?

 

dominicangreen

Weed Robot

Veteran

• Feb 7, 2015

• #11

Pictures of plants would be great too and roots

 

B

Beastmode

New member

• Mar 1, 2017

• #12

That sound stint my ph is going down roots are white as snow upon moving my ph meter in the epic center of my under current system the ppm went from a 120ppm reading to a 300ppm reading and ph went from 5.5-5.1 in a day and the top off res is at 6.5 I pumped 1/3 of the system out and turned on the top off valve and the ph is still at 5.1.Im gonna fully flush system w uc roots and set ph 5.5-6.1 and keep my fingers crossed just about to flippem.
But I need to get this ph under control and ppm's reset.
Day Temp 80-82 night temp 75-78 RH day 70% night 80-90% waiting on a commercial dehuey
Co2 1250ppm