Ph Crashes After Adding Ro

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RoeBuck

RoeBuck

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I've had this happen to me twice now and it's got me stumped. My system ppm was a little high so I removed 7 gallons of solution and added straight RO to dilute it. Before I removed the solution the pH was right around 5.8. The day after it had dropped to 4.9 so I added a bit of pH up. Within 2 more days it crashed to 4.0. I ended up dumping the system and adding fresh nutes. Has anyone else had this happen to them? I'm planning on calling Cultured Solutions and talking to them about it but in the mean time, thought I'd see if anyone here has had a similar experience.
 
dnewsome2

dnewsome2

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RoeBuck said:
I've had this happen to me twice now and it's got me stumped. My system ppm was a little high so I removed 7 gallons of solution and added straight RO to dilute it. Before I removed the solution the pH was right around 5.8. The day after it had dropped to 4.9 so I added a bit of pH up. Within 2 more days it crashed to 4.0. I ended up dumping the system and adding fresh nutes. Has anyone else had this happen to them? I'm planning on calling Cultured Solutions and talking to them about it but in the mean time, thought I'd see if anyone here has had a similar experience.
Click to expand...
I'm not a pro at all man. I'm still learning about Hydroponics but I will try to take a stab at it. It could be that you need to thoroughly clean your system or your plants are at a stage where they are processing nutrients rapidly. Maybe you need more frequent water changes.
 
fatawa

fatawa

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Yur n flower rite?cuz u raise n veg n drop n flower..its very common.drop yur nutes down bro
 
EventHorizan

EventHorizan

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RoeBuck said:
I've had this happen to me twice now and it's got me stumped. My system ppm was a little high so I removed 7 gallons of solution and added straight RO to dilute it. Before I removed the solution the pH was right around 5.8. The day after it had dropped to 4.9 so I added a bit of pH up. Within 2 more days it crashed to 4.0. I ended up dumping the system and adding fresh nutes. Has anyone else had this happen to them? I'm planning on calling Cultured Solutions and talking to them about it but in the mean time, thought I'd see if anyone here has had a similar experience.
Click to expand...
You should prob post that your running a UC systen so that the replys you get our more on target... Im not for sure either one of them guys understand the UC and its very different feeding schedule..

This is a good question... Has anybody else had this problem?
What was your Ec after you put the plain ro back in?
 
EventHorizan

EventHorizan

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EventHorizan said:
You should prob post that your running a UC systen so that the replys you get our more on target... Im not for sure either one of them guys understand the UC and its very different feeding schedule..

This is a good question... Has anybody else had this problem?
What was your Ec after you put the plain ro back in?
Click to expand...
How quickly did you add back? U wouldnt think that it would matter, but maybe it does when you are very low ec? That is just a guess... I know that its hard to ph ro because there isnt no buffering agents in the water. I wonder if adding a very very tiny amount of nutrients to the ro you are adding back. mix them in a 5 gal bucket so its an ec of .03 to try to get it to buffer the ph better when added.. Again just a guess, or what I would try...
 
RoeBuck

RoeBuck

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I'm not a pro at all man. I'm still learning about Hydroponics but I will try to take a stab at it. It could be that you need to thoroughly clean your system or your plants are at a stage where they are processing nutrients rapidly. Maybe you need more frequent water changes.
Click to expand...

I do a thorough cleaning and flush with bleach between every grow so I doubt that is a contributing factor. But thanks anyway.

fatawa said:
Yur n flower rite?cuz u raise n veg n drop n flower..its very common.drop yur nutes down bro
Click to expand...

I understand that. This isn't related as it was a drastic drop, practically overnight. The reason I was adding the RO was because the nute ppm was a bit too high.
 
RoeBuck

RoeBuck

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EventHorizan said:
You should prob post that your running a UC systen so that the replys you get our more on target... Im not for sure either one of them guys understand the UC and its very different feeding schedule..

This is a good question... Has anybody else had this problem?
What was your Ec after you put the plain ro back in?
Click to expand...

I hear you. I just assumed since this is in the UC forum that everyone would get that.

I've not seen this happen to anyone before. I usually wait a day to allow for good circulation before taking a reading. The next morning it had dropped to about 4.9, I added some pH up and the day after it was 4.4. More pH up and it still went down to 4.1. That was when I dumped the system and put in fresh.
 
RoeBuck

RoeBuck

152
43
EventHorizan said:
How quickly did you add back? U wouldnt think that it would matter, but maybe it does when you are very low ec? That is just a guess... I know that its hard to ph ro because there isnt no buffering agents in the water. I wonder if adding a very very tiny amount of nutrients to the ro you are adding back. mix them in a 5 gal bucket so its an ec of .03 to try to get it to buffer the ph better when added.. Again just a guess, or what I would try...
Click to expand...

Since I had removed 7 gallon of solution I added the RO back all at once. My RO runs right around pH 6.35, so I assumed if anything it might slightly raise the pH. But that's something to think about and next time I run into a similar situation maybe give your idea a try. Thanks.
 
RoeBuck

RoeBuck

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Highatollah said:
When was your last drain and refill? In my experience after 2 weeks my ph drops so I change it every 2 weeks. CCH2O says change every 14-21 days.
Click to expand...

I had just changed the system 2 days before. I had added a bit too much nutrients and the ppm was a little high, which was the reason I was adding the RO, to drop the ppm back down a bit. I generally change the system every 18 - 21 days although I've actually gone as long as 33 days just to see how far I could go. I've read in a thread here of someone who never changes their system the whole run. I wouldn't do that because of salt buildup.
 
EventHorizan

EventHorizan

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Not everybody has irrigation water with high alkalinity. In one study from Michigan State University, about 30 percent of the irrigation water tested had alkalinity levels below 40 ppm without any acidification. Even in areas where high alkalinity is considered normal, some growers have switched to low alkalinity sources such as reverse osmosis purified water or rain water.

The primary problem associated with low alkalinity water is a tendency for substrate pH to drop over time, which can cause micronutrient toxicity problems (Figure 3). Low media pH problems are often a result of fertilizer selection. Fertilizers high in ammoniacal nitrogen are acidic, and without any alkalinity in the water to balance the reaction (resist lowering of pH), acidic fertilizers will tend to drive the substrate pH down over time.....


There is the answer... You needed to mix in that 5 gal bucket some ca...
then ph it to 6,
then slowly add it to the system.
let it go 24 hrs and pull a 5 gal bucket from the system, and adjust ph in the bucket to 6.
repeat till at 5.8 or what ever you was shooting for...
Always add it back slow as the water is circulated so fast that rapid changes in ph can shock the plants from what I have read...

I even got an email from a person that had run the UC and he said, for what this is worth, if when adjusting the ph down I over shot my mark, that I had to dump the res and start over. He said not to use ph up.
I really dont know why this is and I havent had time to google and find anybody to substantiate these claims...
But I thought I would add that here.. Have NO IDEA if they is any truth in that..

As much as we know, he might not know shit, and thats why he sold me his UC system after 4 months :)
He did say in his email when i asked him why he was selling it, he said he got caught up in the hype, and that he had a family and realized he was being very stupid...
So I doubt he had very much knowledge of the UC system...
I guess I can always bug CC for the answers lol...
 
EventHorizan

EventHorizan

15,707
438
EventHorizan said:
Not everybody has irrigation water with high alkalinity. In one study from Michigan State University, about 30 percent of the irrigation water tested had alkalinity levels below 40 ppm without any acidification. Even in areas where high alkalinity is considered normal, some growers have switched to low alkalinity sources such as reverse osmosis purified water or rain water.

The primary problem associated with low alkalinity water is a tendency for substrate pH to drop over time, which can cause micronutrient toxicity problems (Figure 3). Low media pH problems are often a result of fertilizer selection. Fertilizers high in ammoniacal nitrogen are acidic, and without any alkalinity in the water to balance the reaction (resist lowering of pH), acidic fertilizers will tend to drive the substrate pH down over time.....


There is the answer... You needed to mix in that 5 gal bucket some ca...
then ph it to 6,
then slowly add it to the system.
let it go 24 hrs and pull a 5 gal bucket from the system, and adjust ph in the bucket to 6.
repeat till at 5.8 or what ever you was shooting for...
Always add it back slow as the water is circulated so fast that rapid changes in ph can shock the plants from what I have read...

I even got an email from a person that had run the UC and he said, for what this is worth, if when adjusting the ph down I over shot my mark, that I had to dump the res and start over. He said not to use ph up.
I really dont know why this is and I havent had time to google and find anybody to substantiate these claims...
But I thought I would add that here.. Have NO IDEA if they is any truth in that..

As much as we know, he might not know shit, and thats why he sold me his UC system after 4 months :)
He did say in his email when i asked him why he was selling it, he said he got caught up in the hype, and that he had a family and realized he was being very stupid...
So I doubt he had very much knowledge of the UC system...
I guess I can always bug CC for the answers lol...
Click to expand...
Another thought is the ro you were adding back, you might have been able to add a couple cups of tap to the ro then ph, then slowly add to system...
We just got to have something in that ro to raise the alkalinity,
so that we can have something to buffer when adding ph down, so that it will stabilize...

Well that is my thoughts at least.................
 
MidwestToker

MidwestToker

1,228
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But what makes me wonder is why his RO is 6.3. My 0 ppm RO is within a few point of 7 pH always.
 
EventHorizan

EventHorizan

15,707
438
MidwestToker said:
But what makes me wonder is why his RO is 6.3. My 0 ppm RO is within a few point of 7 pH always.
Click to expand...
It prob isnt.. Its prob giving a incorrect reading since it has no alkalinity. Ive seen my meter go to invalid reading when putting in to my ro..
Does your actually give a ph reading in 0 ppm ro?
 
H

Highatollah

122
43
Why do you guys even bother taking the PH of your RO before adding nutes? I fill my reservoir with RO, add nutes, and it is usually 6.0 ph by itself. If I need to adjust it then I do.
 
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