Ph Dropping From 5.8 To 3.9 Overnight! What Is Causing This?

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HydroGuy

HydroGuy

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I,d still replace the membrane ! No way to know what the 100 ppm consist of with-out having it tested.
Definitely i ordered all new filters and membrane. The Membrane has to be trashed. I put new filters in and they were dirty in 2 hours so time for a new membrane. Figured might as well get a sterilizer while im at it.
 
MidwestToker

MidwestToker

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Can you explain your rez and nutrient maintenance routine? How are you topping off your rez through the week? Rez change-out?
 
Douglas.C

Douglas.C

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I love how the only real answer gets over looked that you are over feeding
Which damages the roots, causing rot, which drops the pH. Yep. :) Root damage isn't always caused by a biological explosion, you're correct.
 
HydroGuy

HydroGuy

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My rez is not hooked up to a top off. I have 32gallon trash cans that are filled with about 25 gallons of water since this a typical daily feed in flower for me. I mix all nutrients in my daily rez and pump nutrient solution into system. I top of with about 25 gallons a day of nutrient solution. Rez's are cleaned about every other week. I also drain and fill system every 2 weeks to make sure nutrients are balanced. @MidwestToker
 
Dizzy Weasel

Dizzy Weasel

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**fox news bulletin**
H&G lacks trace elements had similar issues started sending water samples to the lab from post flush then post ph plunge and found plants were striping certain trace elements out of water in less than 24hrs.. resolved those issues and it stopped immediately.. just so happens hg came out with there trace additive after I feel they cut the traces out without notifying customers I don't use there line and if I do I add my own trace additives
 
bigdaddyg8

bigdaddyg8

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i am having the same problem? i am in week 8 of flower(current solutions). 9 days ago my PH crashed and my ppm were at 400 on 500 scale. i flushed and brought my ppm 250 3 days later my ph crashed .flushed again added back just municple tap water. the next day my ph crashed again. all root are a bright white and no signs of root rot or slime .the next thing i want to try is push the nutes up to around 500ppm to see if i crash again? i have been using the UC for the last 8years has not always been easy but well worth it !!
I love how the only real answer gets over looked that you are over feeding yet the one guy who uses the "Fox News " scare tactic and tells you it's root rot gets credibility and gets you to buy more equipment you don't need.

I'm in UC. I run municple tap. I run 73 degree water. I run zero air stones or air pumps. My ph stays stable for up to 6 days because I don't go above .6 ec which is 300 tds. All of this is publicly documented on these forums.

It's simple. You are over feeding. Just cut back the nutes.

If simple isn't good enough for you, then feel free to be scared of the root rot you don't have and to open up your wallet and go spend a bunch of money you don't need to spend?
 
Tbone

Tbone

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I find that right at the end of week six my ph will start dropping drastically when feeding heavy. I believe Its because the schedule is now calling for more and more booster and the booster is very acidic. You can ease up on the booster and or do just like what the last fella said and run nutes at a lower TDS asl together. Usually my ppms max out at 400- 500ppm on the 500 scale. Any more and Nute Burn and drastic PH Drop
 
bigdaddyg8

bigdaddyg8

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i am having the same problem? i am in week 8 of flower(current solutions). 9 days ago my PH crashed and my ppm were at 400 on 500 scale. i flushed and brought my ppm 250 3 days later my ph crashed .flushed again added back just municple tap water. the next day my ph crashed again. all root are a bright white and no signs of root rot or slime .the next thing i want to try is push the nutes up to around 500ppm to see if i crash again? i have been using the UC for the last 8years has not always been easy but well worth it !!
on wednesday i pushed my ppm up 530 and set ph to 5.8 today my ppm 460 and my ph rose to 5.9. 4 days till water flush before finishing.
 
Dizzy Weasel

Dizzy Weasel

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on wednesday i pushed my ppm up 530 and set ph to 5.8 today my ppm 460 and my ph rose to 5.9. 4 days till water flush before finishing.
My findings have pointed to something is deficient in solution that causes this and exchanges correct the deficiency then after this trace element is stripped again it drops, raising ppm seems to help as there is more of the element present for the plant to take to correct itself.. you can send water samples to j r peters and do your own due diligence to see if the same thing is causing your drop... I had one strain that kept stripping Mg and I supplemented it instead of wasting 450gal of stock solution every 3-4days when everything was relatively balanced besides the Mg in the systems
 
RFT

RFT

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I love how the only real answer gets over looked that you are over feeding yet the one guy who uses the "Fox News " scare tactic and tells you it's root rot gets credibility and gets you to buy more equipment you don't need.

I'm in UC. I run municple tap. I run 73 degree water. I run zero air stones or air pumps. My ph stays stable for up to 6 days because I don't go above .6 ec which is 300 tds. All of this is publicly documented on these forums.

It's simple. You are over feeding. Just cut back the nutes.

If simple isn't good enough for you, then feel free to be scared of the root rot you don't have and to open up your wallet and go spend a bunch of money you don't need to spend?

Good advice. Im having this same pH issue. I've addressed just about every area thinking I had the culprit. It's been very frustrating. Any advice, is welcome.

(24 recirculatory NFT, auto dosing, chillers, heaters, everything dialed with automation)

  1. Algae - eliminated the algae, and still around weeks 4-5 the pH dropped
  2. Magnesium Deficiency - I read that too much Calcium will cause a Mg deficiency and then the pH will drop. Weird. Why wouldnt this happen sooner than week 4? But I am on well water so Im sure there is plenty of Calcium in the system.
  3. EC Too High - so I set a cap at 1.8 (same issue), so then on my next run set a cap at 1.6 (same issue), so now Im in the process of setting a cap at 1.4 (although, this doesnt make much sense because while at 1.6 in week 3, the pH is stable. Why would it then drop suddenly 4 days into week 4 at the same 1.6 EC?)
  4. Pathogen - the system is pretty dang sterile
  5. Root Rot - zero signs of root rot, since eliminating the algae the roots are clean white
  6. Too Much Nitrogen - could this be the problem? Im running FloraDuo A & B by the book, not sure why nitrogen would be in excess since FloraDuo was designed for cannabis
  7. Heavy P-K Feeding - I've read that when plants eat up the available P-K the pH will drop. I suppose this could be the issue and I could just increase the Liquid Kool Bloom. They are well into flower and needing a lot of nutes. Typically at week 4 I've also seen my plants "plateau" in their development. Not showing signs of deficiency tho. Everything is SUPER healthy looking. If P-K was in short supply, would the plants show a deficiency or just not develop enough bud size? I've been very disappointed with my cola size.
  8. Healthy Hungry Roots - I've read that roots create acidity, especially when they are eating a lot. Could this be the problem? Just do a flush and get them fresh nutes? I already do weekly reservoir changes. I could change out sooner if needed but that seems really excessive. I have a 400 gallon resi for 1100 plants.
 
RFT

RFT

119
43
My current theory is that the plants are uptaking a nutrient in heavy doses. Because all the synthetic nutes have buffering properties to them, once that nute has been depleted, the pH chemistry is thrown off.

Short term solution is to do a resi flush. New nutes added. Depleted nute is replenished.

Long term solution is play with NPK ratios a little. Might need less N and more P-K.

Higher EC isn’t necessarily the answer but rather an adjustment to the ratios based on what the plants are asking for. Likely more P-K.

Increasing overall EC might only result in too much of a nutrient that could lead to lockout. Gotta fix the ratios before pushing the EC (if pushing the EC is even necessary).

Heavy eating causing roots to create acidity only adding to the problem.

Sound diagnosis?
 
Aqua Man

Aqua Man

26,480
638
My current theory is that the plants are uptaking a nutrient in heavy doses. Because all the synthetic nutes have buffering properties to them, once that nute has been depleted, the pH chemistry is thrown off.

Short term solution is to do a resi flush. New nutes added. Depleted nute is replenished.

Long term solution is play with NPK ratios a little. Might need less N and more P-K.

Higher EC isn’t necessarily the answer but rather an adjustment to the ratios based on what the plants are asking for. Likely more P-K.

Increasing overall EC might only result in too much of a nutrient that could lead to lockout. Gotta fix the ratios before pushing the EC (if pushing the EC is even necessary).

Heavy eating causing roots to create acidity only adding to the problem.

Sound diagnosis?
Just heading to a meeting if it's not a sterile system a lot can be caused by microbes but I'll get into that after.
 

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