PH rises 0.1 every 24 hours

kratosxxl

Active Member
Hi everyone , im new here so no yelling
This is my first grow i got clones from friend of mine , he cloned them from flowering stage and i guess messed up cycle and clones started to flower (it had tiny buds and have a strong smell )while being 7 inch tall.
1st week everything was i was trying to flip them back to veg ,now im on a 2nd week and ph started to raise slowly 6.0-6.1-6.2 in course of 3 days
8*4 tent
PPM 370
Temp 74 Rez
Tent temp 74
PH -6.2
Im using floranova bloom with some silica and cal mag. Roots already coming out of netpots and no rot or anything but i feel this ph rise is not how it should be am i right ?
I dont have Chiller ATM but planning on it
 

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toto420

Member
Temp rez I dont care to certain point so dont bother with a chiller for now, this is expensive.
But 74 (23 c ) is very low in my opinion. I go that low for bloom only at night/ lights off.
But in veg I'd go 26c ( 79f ) minimum lights on and off. They seem to be cold.
 

kratosxxl

Active Member
So my pump is about 1100gph a lot of flow.
I wasnt paying too much attention to water level cuz i need to turn off the pump to see it, thats the reason im still think about auto top off.
 

Larry3215

Well-Known Member
There are several different things that can cause drastic PH increases.

1) Biological action. It could be from algae, or other bacterial growths in your rez, or in your case, also in the buckets. As far as I know the only solution for this is to use IN-organic nutes with absolutely NO ingredients derived from anything organic or plant based. Something like Jacks 321 hydro will work great, but be careful if you use any cal/mag, or other additives that have ANYTHING derived from plant material.

I had this exact problem when I was using Advanced Nutes PH perfect line, Mega Crop, and Fox Farm nutes. Once I switched to Jacks321, that all went away and I was able to reduce the chlorine I add to next to nothing. My rez stays fresh for up to 9 days between refills. I am drain to waste in an AAA setup, so no root exudates to worry about.

2) It could also be from the roots interacting with the solution, but that is dependent on your EC level to some degree, but if you have bad bacterial growths, your screwed. This is less likely in your case because your roots are still small.

Bottom line - do not ever use anything organic in hydro.

3) The calcium/alkalinity of your water is the next one. Every time you PH down, the dissolved C02 level increases, which lowers the PH by the formation of carbonic acid. Unfortunately, when you aerate, the excess C02 in the water leaves the solution, which lowers the concentration of carbonic acid, which raises the PH. The more you aerate, the faster the PH goes up. The worse your calcium problem is, the higher it will go. Basically, your water has what I think of as a 'natural' or preferred PH level once every thing equalizes - dissolved C02 mainly. When you PH down, then aerate, it wants to go back to that PH. How bad this is depends on your water, but if its well water, there is an excellent chance you have this problem to some degree.

4) The other thing is temperature. I just confirmed this recently in my grow. I try to keep my rez water around 65F as a max, but that water feeds down to a small holding tank that is about 1 liter. That small tank is used to adjust the water level for the AAA nozzles to siphon from, so it has to be near the root chamber. That area where the tank sits varies from the hi 70's to the hi 80's temperature wise because I have to heat my root chamber or it stays too cold. So that water in the tank varies from the upper 70's to mid 80's, while my rez stays at no more than 65F and often down to 55F when I do a rez refill or add ice to keep it cool.

Here is where the problem arises. The dissolved C02 level goes DOWN when temperature increases, and goes UP when temperature decreases.

Remember the dissolved C02 forms carbonic acid which is what lowers the PH. So, any time there is a temperature change, the carbinic acid level changes which changes your PH. In my case, when the rez temp is near 65F and the siphon tank is down near 75 F, the PH goes up by about 0.1. When the rez is cold at 55F and the siphon tank is at 85F, the PH difference will be 0.3 to 0.4. So when I was setting my rez to 5.8, my roots were being sprayed at 5.9 to 6.2 PH.

YKeeping your water temps higher means your PH will want to stay higher. Keeping your rwater temps lower means your PH will want to stay lower.

I have been fighting all these issues for two years trying to sort out why my PH was impossible to control. It turns out I have all of them. My solutions were as follows.

1) Never ever ever ever ever use anything organic in the rez - ever. Bacteria and algae just love that crap and they grow like mad when its available. By the way - this very much includes any so called "beneficial bacteria". Dont use it. I also am absolutely fanatical about light discipline as far as light getting into the rez, any fitting, and all tubing. Algae wont grow if there is zero light, but you must check all fittings, and pipes, buckets, lids etc.

2) I dont have to worry about my roots messing up the PH because they never touch the rez water or the siphon tank water. Once the roots get sprayed, the runnoff get tossed out. I am drain to waste. In your case, as long as the EC is close, that should be easily manageable.

3)My alkalinity/calcium problem isnt too extreme, but it is there. My water likes to be at around 6.4-6.5 PH. I handle that by doing the minimum amount of aeration I can get by with in the rez. Plus, I keep the rez remps low - below 65. I use an aquarium pump in my rez to keep it stirred up and it flumes the water surface. It also has an air line that sucks in air and puts out small bubbles when the pump runs. I only run the pump 1 minute out of every 15. Just enough to be sure no anerobic bacteria can get started. I get all the aeration I need by the air atomization from the spray nozzles, and the micron sized droplets. You wont want to keep your water as cold as I do - your roots wont like it. 68-70 is probably the ideal range for your situation.

Hope that helps, and good luck!!!
 
Last edited:
A 0.1 rise every 24 hours sounds normal to me. Your ph rises as your plant uses up nutrients from the water. That’s normal, as long as it’s not jumping drastically over a short period of time ( .1 in 24 hours is not drastic).

If that .1 rise stays consistent from day to day and you’re setting your ph at, say 5.5, that would mean it would rise to 6.2 over a 7 day period (which is when I personally do my water change). That sounds about perfect to me. I set my ph at 5.5 and let it rise to 6.3 before adjusting it back to 5.5. I find I get a better taste when I let the plants go through a full ph swing like that. (If you’re not doing water changes, or doing then every 10-14 days, then just bring your ph back down to 5.5 when it gets to 6.3)


Also, Personally I wouldn’t let your reservoir temps get much higher.
75 is about the max before you can start having problems with root rot and bacteria and stuff like that (sure you can let them get higher but you’re playing with fire IMO). I always keep my reservoir temperature below 70 (but I use a res chiller).
 

fragileassassin

Well-Known Member
Have you let it go to see how high it goes?
I've found that mine settles in the 6.2-6.4 range in my flower system with airstones depending on the current mix. No matter how much I try to fight it, itll settle back to the same within a couple days. It doesnt keep going up passed that though and its within range so I just leave it be.
 

myke

Well-Known Member
Have you let it go to see how high it goes?
I've found that mine settles in the 6.2-6.4 range in my flower system with airstones depending on the current mix. No matter how much I try to fight it, itll settle back to the same within a couple days. It doesnt keep going up passed that though and its within range so I just leave it be.
Ya agreed less headaches ,plants seam to like the wondering ph even if it goes out of range.I check every two days but dont adjust it if its not perfect.
 

kratosxxl

Active Member
Have you let it go to see how high it goes?
I've found that mine settles in the 6.2-6.4 range in my flower system with airstones depending on the current mix. No matter how much I try to fight it, itll settle back to the same within a couple days. It doesnt keep going up passed that though and its within range so I just leave it be.
I have not but i think i will just to see how high it goes i also use h2o2 once a week u know just to kill stuff in system
 

kratosxxl

Active Member
Also is it true that if ppm is low and plant eating that will raise ph ? If yes so raising ppm should fix it ?
 

kratosxxl

Active Member
There are several different things that can cause drastic PH increases.

1) Biological action. It could be from algae, or other bacterial growths in your rez, or in your case, also in the buckets. As far as I know the only solution for this is to use IN-organic nutes with absolutely NO ingredients derived from anything organic or plant based. Something like Jacks 321 hydro will work great, but be careful if you use any cal/mag, or other additives that have ANYTHING derived from plant material.

I had this exact problem when I was using Advanced Nutes PH perfect line, Mega Crop, and Fox Farm nutes. Once I switched to Jacks321, that all went away and I was able to reduce the chlorine I add to next to nothing. My rez stays fresh for up to 9 days between refills. I am drain to waste in an AAA setup, so no root exudates to worry about.

2) It could also be from the roots interacting with the solution, but that is dependent on your EC level to some degree, but if you have bad bacterial growths, your screwed. This is less likely in your case because your roots are still small.

Bottom line - do not ever use anything organic in hydro.

3) The calcium/alkalinity of your water is the next one. Every time you PH down, the dissolved C02 level increases, which lowers the PH by the formation of carbonic acid. Unfortunately, when you aerate, the excess C02 in the water leaves the solution, which lowers the concentration of carbonic acid, which raises the PH. The more you aerate, the faster the PH goes up. The worse your calcium problem is, the higher it will go. Basically, your water has what I think of as a 'natural' or preferred PH level once every thing equalizes - disolved C)2 mainly. When you PH down, then aerate, it wants to go back to that PH. How bad this is depends on your water, but if its well water, there is an excellent chance you have this problem to some degree.

4) The other thing is temperature. I just confirmed this recently in my grow. I try to keep my rez water around 65F as a max, but that water feeds down to a small holding tank that is about 1 liter. That small tank is used to adjust the water level for the AAA nozzles to siphon from, so it has to be near the root chamber. That area where the tank sits varies from the hi 70's to the hi 80's temperature wise because I have to heat my root chamber or it stays too cold. So that water in the tank varies from the upper 70's to mid 80's, while my rez stays at no more than 65F and often down to 55F when I do a rez refill or add ice to keep it cool.

Here is where the problem arises. The dissolved C02 level goes DOWN when temperature increases, and goes UP when temperature decreases.

Remember the dissolved C02 forms carbonic acid which is what lowers the PH. So, any time there is a temperature change, the carbinic acid level changes which changes your PH. In my case, when the rez temp is near 65F and the siphon tank is down near 75 F, the PH goes up by about 0.1. When the rez is cold at 55F and the siphon tank is at 85F, the PH difference will be 0.3 to 0.4. So when I was setting my rez to 5.8, my roots were being sprayed at 5.9 to 6.2 PH.

YKeeping your water temps higher means your PH will want to stay higher. Keeping your rwater temps lower means your PH will want to stay lower.

I have been fighting all these issues for two years trying to sort out why my PH was impossible to control. It turns out I have all of them. My solutions were as follows.

1) Never ever ever ever ever use anything organic in the rez - ever. Bacteria and algae just love that crap and they grow like mad when its available. By the way - this very much includes any so called "beneficial bacteria". Dont use it. I also am absolutely fanatical about light discipline as far as light getting into the rez, any fitting, and all tubing. Algae wont grow if there is zero light, but you must check all fittings, and pipes, buckets, lids etc.

2) I dont have to worry about my roots messing up the PH because they never touch the rez water or the siphon tank water. Once the roots get sprayed, the runnoff get tossed out. I am drain to waste. In your case, as long as the EC is close, that should be easily manageable.

3)My alkalinity/calcium problem isnt too extreme, but it is there. My water likes to be at around 6.4-6.5 PH. I handle that by doing the minimum amount of aeration I can get by with in the rez. Plus, I keep the rez remps low - below 65. I use an aquarium pump in my rez to keep it stirred up and it flumes the water surface. It also has an air line that sucks in air and puts out small bubbles when the pump runs. I only run the pump 1 minute out of every 15. Just enough to be sure no anerobic bacteria can get started. I get all the aeration I need by the air atomization from the spray nozzles, and the micron sized droplets. You wont want to keep your water as cold as I do - your roots wont like it. 68-70 is probably the ideal range for your situation.

Hope that helps, and good luck!!!
Thank you a lot :))
 

Larry3215

Well-Known Member
Have you let it go to see how high it goes?
I've found that mine settles in the 6.2-6.4 range in my flower system with airstones depending on the current mix. No matter how much I try to fight it, itll settle back to the same within a couple days. It doesnt keep going up passed that though and its within range so I just leave it be.
See poin 3 In my post above

3) The calcium/alkalinity of your water is the next one. Every time you PH down, the dissolved C02 level increases, which lowers the PH by the formation of carbonic acid. Unfortunately, when you aerate, the excess C02 in the water leaves the solution, which lowers the concentration of carbonic acid, which raises the PH. The more you aerate, the faster the PH goes up. The worse your calcium problem is, the higher it will go. Basically, your water has what I think of as a 'natural' or preferred PH level once every thing equalizes - disolved C02 mainly. When you PH down, then aerate, it wants to go back to that PH. How bad this is depends on your water, but if its well water, there is an excellent chance you have this problem to some degree.
 

kratosxxl

Active Member
See poin 3 In my post above

3) The calcium/alkalinity of your water is the next one. Every time you PH down, the dissolved C02 level increases, which lowers the PH by the formation of carbonic acid. Unfortunately, when you aerate, the excess C02 in the water leaves the solution, which lowers the concentration of carbonic acid, which raises the PH. The more you aerate, the faster the PH goes up. The worse your calcium problem is, the higher it will go. Basically, your water has what I think of as a 'natural' or preferred PH level once every thing equalizes - disolved C02 mainly. When you PH down, then aerate, it wants to go back to that PH. How bad this is depends on your water, but if its well water, there is an excellent chance you have this problem to some degree.
Hey man i dont know were u learned this stuff but its pretty amazing information , thank you a lot

Also added h2o2 and i found out that bottom of netpots have some foam is that a sign for algae ?
 

myke

Well-Known Member
There are several different things that can cause drastic PH increases.

1) Biological action. It could be from algae, or other bacterial growths in your rez, or in your case, also in the buckets. As far as I know the only solution for this is to use IN-organic nutes with absolutely NO ingredients derived from anything organic or plant based. Something like Jacks 321 hydro will work great, but be careful if you use any cal/mag, or other additives that have ANYTHING derived from plant material.

I had this exact problem when I was using Advanced Nutes PH perfect line, Mega Crop, and Fox Farm nutes. Once I switched to Jacks321, that all went away and I was able to reduce the chlorine I add to next to nothing. My rez stays fresh for up to 9 days between refills. I am drain to waste in an AAA setup, so no root exudates to worry about.

2) It could also be from the roots interacting with the solution, but that is dependent on your EC level to some degree, but if you have bad bacterial growths, your screwed. This is less likely in your case because your roots are still small.

Bottom line - do not ever use anything organic in hydro.

3) The calcium/alkalinity of your water is the next one. Every time you PH down, the dissolved C02 level increases, which lowers the PH by the formation of carbonic acid. Unfortunately, when you aerate, the excess C02 in the water leaves the solution, which lowers the concentration of carbonic acid, which raises the PH. The more you aerate, the faster the PH goes up. The worse your calcium problem is, the higher it will go. Basically, your water has what I think of as a 'natural' or preferred PH level once every thing equalizes - dissolved C02 mainly. When you PH down, then aerate, it wants to go back to that PH. How bad this is depends on your water, but if its well water, there is an excellent chance you have this problem to some degree.

4) The other thing is temperature. I just confirmed this recently in my grow. I try to keep my rez water around 65F as a max, but that water feeds down to a small holding tank that is about 1 liter. That small tank is used to adjust the water level for the AAA nozzles to siphon from, so it has to be near the root chamber. That area where the tank sits varies from the hi 70's to the hi 80's temperature wise because I have to heat my root chamber or it stays too cold. So that water in the tank varies from the upper 70's to mid 80's, while my rez stays at no more than 65F and often down to 55F when I do a rez refill or add ice to keep it cool.

Here is where the problem arises. The dissolved C02 level goes DOWN when temperature increases, and goes UP when temperature decreases.

Remember the dissolved C02 forms carbonic acid which is what lowers the PH. So, any time there is a temperature change, the carbinic acid level changes which changes your PH. In my case, when the rez temp is near 65F and the siphon tank is down near 75 F, the PH goes up by about 0.1. When the rez is cold at 55F and the siphon tank is at 85F, the PH difference will be 0.3 to 0.4. So when I was setting my rez to 5.8, my roots were being sprayed at 5.9 to 6.2 PH.

YKeeping your water temps higher means your PH will want to stay higher. Keeping your rwater temps lower means your PH will want to stay lower.

I have been fighting all these issues for two years trying to sort out why my PH was impossible to control. It turns out I have all of them. My solutions were as follows.

1) Never ever ever ever ever use anything organic in the rez - ever. Bacteria and algae just love that crap and they grow like mad when its available. By the way - this very much includes any so called "beneficial bacteria". Dont use it. I also am absolutely fanatical about light discipline as far as light getting into the rez, any fitting, and all tubing. Algae wont grow if there is zero light, but you must check all fittings, and pipes, buckets, lids etc.

2) I dont have to worry about my roots messing up the PH because they never touch the rez water or the siphon tank water. Once the roots get sprayed, the runnoff get tossed out. I am drain to waste. In your case, as long as the EC is close, that should be easily manageable.

3)My alkalinity/calcium problem isnt too extreme, but it is there. My water likes to be at around 6.4-6.5 PH. I handle that by doing the minimum amount of aeration I can get by with in the rez. Plus, I keep the rez remps low - below 65. I use an aquarium pump in my rez to keep it stirred up and it flumes the water surface. It also has an air line that sucks in air and puts out small bubbles when the pump runs. I only run the pump 1 minute out of every 15. Just enough to be sure no anerobic bacteria can get started. I get all the aeration I need by the air atomization from the spray nozzles, and the micron sized droplets. You wont want to keep your water as cold as I do - your roots wont like it. 68-70 is probably the ideal range for your situation.

Hope that helps, and good luck!!!
Excellent bit of info,I have hard calcium rich water.I have found when setting a new res ph will always bounce back to its neutral ph of 7.5 it takes an awful amount of ph down before it stabilized.I use air stones and waterfalls.Ive recently switched to GH hardwater micro/bloom and now I dont have to add ph down.Whats in that stuff?
 
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