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

[HydroGuy]

This is the 2nd day in a row ph has dropped a whole 2.0 overnight! Last night i checked all the roots, cleaned filters and checked pipes for clogs. Everything looked good no signs of rot or slime in the system but ph keeps drastically dropping. If its not root rot or slime is it possible pathogens are getting in through my ro filter. I am over due for changing these but still didnt think it could make that much of a difference. I have got quite a few undercurrent runs under my belt but have never seen ph swing like this! Any ideas on the source of the problem here?

 

[HydroGuy]

I did also do a flush then filled with half strength nutrients thinking it could be nutrients arent balanced but this didnt help.

 

[mojavegreen]

The only time I experienced that I was running too low EC.

 

[MidwestToker]

Same nutrients? My pH drops from excessive nutrients. Some nutrients are pH buffered better than others also. Do you know what your ppm out of the RO are?

 

[mojavegreen]

I was running 600 to 700 ppm (500 scale) in bloom when it was dropping. I now run 850 to 950 with stable results.
Same nutes. Tried a whole run with lowered ec as experiment. Low yields and ph instability were my rewards.

 

[MidwestToker]

I was running 600 to 700 ppm (500 scale) in bloom when it was dropping. I now run 850 to 950 with stable results.
Same nutes. Tried a whole run with lowered ec as experiment. Low yields and ph instability were my rewards.

I'm running 450-550 ppm max.

 

[mojavegreen]

Guess that ain't it then.

 

[HydroGuy]

Hmm i will try bumping up EC. Im usually at about 1.3-1.4 in week 4 of flower. Usually doing a flush then refilling with a half strength nutrient solution doesnt mess up my ph and fixes nutrient problems but this is just wierd. My water out of ro is 0.2 EC so definitely need to change filters. Think bad ro filters could be the cause?

 

[HydroGuy]

Currently running week 4 of flower...
Aqua flakes a/b
Drip clean
Bud xl
Uc roots
Big bud
Calimagic

 

[mojavegreen]

with all them ingredients hard to say. I would simplify your recipe.

 

[HydroGuy]

with all them ingredients hard to say. I would simplify your recipe.

Well drip clean just prevents salt build up in lines and UC roots is a sterilizer, neither effect ph or EC. So its really only a 4 part nutrient feed. Been using this feed schedule for years and never had a problem.

My main concern is if this could be some kind of pathogen caused by bad filters or water source itself. But the roots look healthy so im just confused

 

[MidwestToker]

Hmm i will try bumping up EC. Im usually at about 1.3-1.4 in week 4 of flower. Usually doing a flush then refilling with a half strength nutrient solution doesnt mess up my ph and fixes nutrient problems but this is just wierd. My water out of ro is 0.2 EC so definitely need to change filters. Think bad ro filters could be the cause?

I usually replace my membrane when it climbs above 15 ppm.

 

[HydroGuy]

I usually replace my membrane when it climbs above 15 ppm.

Yeah im thinking it has to be related to the RO. I bought new carbon and sediment filters today but maybe the membrane needs to be replaced as well. Thanks!

 

[palm eezy]

How old is the batch?

 

[HydroGuy]

How old is the batch?

Not sure what you are asking here?

 

[Douglas.C]

Ph dropping like a rock is almost always root rot beginning, takes a minute for the roots to start showing damage. Undercurrent has areas which can breed bacteria, yet not affect the roots right off as well.

 

[HydroGuy]

Ph dropping like a rock is almost always root rot beginning, takes a minute for the roots to start showing damage. Undercurrent has areas which can breed bacteria, yet not affect the roots right off as well.

Yeah that was my fear. I drained a filled the system 3 times ran H202 and a strong dose of UC roots. Ph is holding steady now! Checked every inch of that system last night for pythium and root rot but thankfully no signs yet. I will just have to keep a close eye on roots rest of grow and make sure no dirty microscopic bastards are thinking my system is there new home. Still unsure of the source of problem. Only conclusion i can make is some bacteria made an attempt at an attack but im thinking they got killed off before they could become residents of my system haha. Otherwise plants and roots look healthy.

 

[HydroGuy]

Im thinking im going to pick up a uv sterilizer for my RO also. I think i may have held off the first attack but im worried if it will happen again before harvest.

 

[FooDoo]

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?

 

[HydroGuy]

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?

A uv sterilizer kit costs me 60$ wouldnt really classify that as alot of money when talking about a 12k watt room. For 99% of strains i would agree an EC of 1.4 week 4 of flower would be way too much. The agent orange im growing in there is by far the most aggressive and heavy feeding strain i have seen in my 5 years of growing. I can feed and bump system up to 1.5 and within 12 hours its at 1.2. Agent orange eats and grows like nothing i have seen. Most strains i am at an EC of 1 at this stage.

That being said the few days prior to this i did try to push the plants harder since this is there peak point of nutrient uptake. Initially i would have related this drop to overfeeding but since the first 2 times i drained and filled to rinse system ph still dropped. So i assumed it had to be another issue which is where potential root rot became the number 1 suspect. After throughly inspecting system and finding no signs of rot i can only conclude there was some form of bacteria or i locked out nutrients from an overfeed. Overfeeding didnt seem like the main suspect since problems still persisted after 2 times of completely draining and filling system.