PH changing in hydro to rapidly.

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STR8QU4D5

Active Member
Hi folks. Can't figure out why the PH keeps jumping up everytime after the pumps turn on and move through the rockwool. I can't seem to stabilize the PH at all. I start the fresh res out at 5.7-5.8 and after the first feeding it jumps to 6.1-6.2. Then after the second feeding it jumps to 6.5-6.6. The pump turns on 3 times daily. So this jump happens as soon as after the first feeding. No matter how many times I correct the PH it won't stay stabilized, whats going on? Using RO with DNF, CalMag and 3% hydrogen peroxide. The res also has a oxygenator to keep things moving. Also, Im using a properly calibrated PH probe that sits in the res, so its not the meter. Can't figure out if its the rockwool. I prepped them for 12 hours before using them. I can't be adjusting the PH 3 times a day. Is there any solution I can add to prevent this from happening?
 
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indawindica

indawindica

Well-Known Member
Sounds like ph drift. Have you ever just let it be and checked it the next morning? And what brand of ph down are you using?
 
blackforest

blackforest

Well-Known Member
STR8QU4D5 said:
Hi folks. Can't figure out why the PH keeps jumping up everytime after the pumps turn on and move through the rockwool. I can't seem to stabilize the PH at all. I start the fresh res out at 5.7-5.8 and after the first feeding it jumps to 6.1-6.2. Then after the second feeding it jumps to 6.5-6.6. The pump turns on 3 times daily. So this jump happens as soon as after the first feeding. No matter how many times I correct the PH it won't stay stabilized, whats going on? Using RO with DNF, CalMag and 3% hydrogen peroxide. The res also has a oxygenator to keep things moving. Also, Im using a properly calibrated PH probe that sits in the res, so its not the meter. Can't figure out if its the rockwool. I prepped them for 12 hours before using them. I can't be adjusting the PH 3 times a day. Is there any solution I can add to prevent this from happening?
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Not sure what stage you are in, or how many/big cubes you have, but rockwool itself is alkaline (high ph). Even if you treated them, according to your situation, I would say that is a good variable to take into consideration. If they are new, which it sounds like, they should stabilize themselves after a few feedings I'm guessing. I can't think of any other variable causing a higher ph after feeding, especially with such a noticeable slight ph drift.
 
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STR8QU4D5

Active Member
blackforest said:
Not sure what stage you are in, or how many/big cubes you have, but rockwool itself is alkaline (high ph). Even if you treated them, according to your situation, I would say that is a good variable to take into consideration. If they are new, which it sounds like, they should stabilize themselves after a few feedings I'm guessing. I can't think of any other variable causing a higher ph after feeding, especially with such a noticeable slight ph drift.
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yeah, its really frustrating. I treated them before using them. I ran the pump for 3 hours straight and then the PH finally stabilized, but then I woke up this morning and the PH had jumped to 6.9 after the first feeding this morning. Really annoying.. Is there anything I can add to prevent the jump in PH? It most likely is the rockwool, or its the plants sucking all the acidic nutes out. Maybe I need to increase the nutes from 700 to 900. Maybe that will prolong it.
 
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STR8QU4D5

Active Member
indawindica said:
Sounds like ph drift. Have you ever just let it be and checked it the next morning? And what brand of ph down are you using?
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I flushed the cubes with the pump on pretty hard yesterday for 3 hours, and then the PH stabilized. But then after the first feeding this morning, the PH jumped to 6.9. Im using 15 gallon res. The plants aren't doing so good because the PH is messing with them.
 
Purpsmagurps

Purpsmagurps

Well-Known Member
reservoir temps? hydroguard? bacteria growth ? are you chilling your water?

Humic acids help stabilize ph, as well as beneficial bacteria.
 
Anon Emaus

Anon Emaus

Well-Known Member
Pics of your system and plant? How long has this been going on? How old is the plant? What's the EC?
 
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VegasWinner

Well-Known Member
STR8QU4D5 said:
Hi folks. Can't figure out why the PH keeps jumping up everytime after the pumps turn on and move through the rockwool. I can't seem to stabilize the PH at all. I start the fresh res out at 5.7-5.8 and after the first feeding it jumps to 6.1-6.2. Then after the second feeding it jumps to 6.5-6.6. The pump turns on 3 times daily. So this jump happens as soon as after the first feeding. No matter how many times I correct the PH it won't stay stabilized, whats going on? Using RO with DNF, CalMag and 3% hydrogen peroxide. The res also has a oxygenator to keep things moving. Also, Im using a properly calibrated PH probe that sits in the res, so its not the meter. Can't figure out if its the rockwool. I prepped them for 12 hours before using them. I can't be adjusting the PH 3 times a day. Is there any solution I can add to prevent this from happening?
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bubbling water raises ph levels. I use an alternate method of introducing oxygen into water. 12" drop method. peace
 
loftygoals

loftygoals

Well-Known Member
VegasWinner said:
bubbling water raises ph levels. I use an alternate method of introducing oxygen into water. 12" drop method. peace
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This is not true. Bubbling vs waterfall will make no difference when it comes to pH. pH is a reflection of free hydrogen ions in your solution.

If you bubble CO2 through the water (eg CO2 supplemented air) then you get:

CO2 + H2O <-> H2CO3

So you make carbonic acid. The carbonic acid then ionises and forms an equilibrium in the solution, increasing free H ions and making your solution more acidic. Without CO2 supplementation the amount of CO2 in environmental air forms an equilibrium at around pH 5.65 (in RO water with no nutes to buffer). In a CO2 supplemented room the pH could get much lower as more carbonic acid is produced before reaching equilibrium with the enriched atmosphere.

It is the CO2 and not the bubbling itself that make "oxygenated" water increasingly acidic. If waterfalls agitate the water as effectively as an air pump then the effect would be exactly the same.
 
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VegasWinner

Well-Known Member
loftygoals said:
This is not true. Bubbling vs waterfall will make no difference when it comes to pH. pH is a reflection of free hydrogen ions in your solution.

If you bubble CO2 through the water (eg CO2 supplemented air) then you get:

CO2 + H2O <-> H2CO3

So you make carbonic acid. The carbonic acid then ionises and forms an equilibrium in the solution, increasing free H ions and making your solution more acidic. Without CO2 supplementation the amount of CO2 in environmental air forms an equilibrium at around pH 5.65 (in RO water with no nutes to buffer). In a CO2 supplemented room the pH could get much lower as more carbonic acid is produced before reaching equilibrium with the enriched atmosphere.

It is the CO2 and not the bubbling itself that make "oxygenated" water increasingly acidic. If waterfalls agitate the water as effectively as an air pump then the effect would be exactly the same.
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too many years with the opposite experience, and science agrees with me. Both are NOT equal. if they were I would have to use ph up/down and I do nt use those products at all. never have never will. waterfall effect leaves water oxygenated. But that is not the problem at hand. bubbling causing ph levesl to change overnight. I use waterfall eff3ect and do not have the problem. When I used a bubbler, that was the routine. ph up/down due to the effect. Now I have custom system that allows ph to remain just like it started, no ph up/down required, and I use tap water too. bubbling causes ph to rise. period. peace.
 
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STR8QU4D5

Active Member
VegasWinner said:
bubbling water raises ph levels. I use an alternate method of introducing oxygen into water. 12" drop method. peace
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I knew it! I suspected this! Im glad you brought it up, I couldn't find anything on this. Can you show me an example of alternatives please? Thanks in advance!
 
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VegasWinner

Well-Known Member
STR8QU4D5 said:
I knew it! I suspected this! Im glad you brought it up, I couldn't find anything on this. Can you show me an example of alternatives please? Thanks in advance!
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I use the waterfall effect instead. I use clone spinners with a a submersed pump allowing ph to remain stable always. take a 2 gallonbucket get a small submersible pump like this ->http://www.ebay.com/itm/like/321603199092?lpid=82&chn=ps&ul_noapp=true attach a spinning feeding like this ->http://www.greenerhydroponics.com/Aeroponic-Clone-Spinner-360_p_76236.html?gclid=CjwKEAjwkPS6BRD2ioKR7K245jASJAD1ZqHOVk8fXwRwcaTZFe0LT9p2VXyzwyODlZV_0Ca9XOknmRoCuuvw_wcB use some pvc to rig a connection. put a cap on the pvc drill and place the spinner at the top. place in a bucket at least 3 gallons and your problem is solved. I left bubbling years ago because of ph issues. I use exclusive waterfall effect now. no ph problems and great plants. good luck. peace
 
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VegasWinner

Well-Known Member
STR8QU4D5 said:
I knew it! I suspected this! Im glad you brought it up, I couldn't find anything on this. Can you show me an example of alternatives please? Thanks in advance!
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another method is the drip feed method. works well and ph does not change unless you are running air pumps in the rez. peace
 
S

STR8QU4D5

Active Member
VegasWinner said:
another method is the drip feed method. works well and ph does not change unless you are running air pumps in the rez. peace
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Awesome, thank you. When you say drip feed, your not referring to anything in the rez are you? just the actual concept of drip deeding? Does this oxygenate too?
 
swedsteven

swedsteven

Well-Known Member
I put my hydroton in a 20 litter bucket fill it up with water then ph it to 5.0 then Come next Day check if they move if yes add ph down until they stabalize after that it wont move that much
 
MeJuana

MeJuana

Well-Known Member
Yes the pH of a solution can change without introducing more "ions".
http://scienceinhydroponics.com/2010/05/how-to-have-a-constant-ph-in-hydroponics-no-more-corrections-o.html

When I am dealing with constant pH drift I hard buffer my solution. Add Silica first like always if you are using it. Use pH UP to bugger to a pH of 10. Now use pH down to buffer to a pH of 7. Mix your nutrients in. Set your pH to 5.5 if it's been drifting up and 5.8 if it has been drifting down. If that doesn't solve the problem then the plants are eating a major buffer. Nitrogen, Phosphorus or something is being taken by the plants at a high rate. When you figure out what is being taken the pH drift should slow down, hope that makes sense.
 
S

STR8QU4D5

Active Member
MeJuana said:
Yes the pH of a solution can change without introducing more "ions".
http://scienceinhydroponics.com/2010/05/how-to-have-a-constant-ph-in-hydroponics-no-more-corrections-o.html

When I am dealing with constant pH drift I hard buffer my solution. Add Silica first like always if you are using it. Use pH UP to bugger to a pH of 10. Now use pH down to buffer to a pH of 7. Mix your nutrients in. Set your pH to 5.5 if it's been drifting up and 5.8 if it has been drifting down. If that doesn't solve the problem then the plants are eating a major buffer. Nitrogen, Phosphorus or something is being taken by the plants at a high rate. When you figure out what is being taken the pH drift should slow down, hope that makes sense.
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Nice idea. Ill give it a try. Why would I PH to 10, to then just PH to 5.5 in my case. Isn't using PH UP and PH DOWN at the same time not good to do?
 
MaiNiaK420

MaiNiaK420

Well-Known Member
Raise your nutrient levels.
I run mine at 1200 to 1500 ppm using tap water. When I first started I would use ph adjusters all the time. Once you find the right ppm, the ppm should stay the same as the water level drops. At this point you'll notice your ph doesn't fluxuate as much. (I also don't use rockwool) So I don't have any experience with it.
My ph probe broke on my trimeter a long time ago. Haven't needed it, so I have never replaced it. The only other thing that will mess up ph in my experience is root rot.

Good luck, hope you figure this out.
 
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