Grow Mediums Huge pH spiking

[Sublime Rasta]

I moved, and I am now using city water instead of well water. In 24 hours I spike from 5.5 to 7.2. I have tried general hydroponics pH down and sulfuric acid. Both rapidly increase over a 24 hour period. At first I thought maybe I didn't soak my growing media long enough, so I put two glasses of water under my sink for 24 hours with a pH of 5.8. The same exact pH spiking occurred. What is my problem?

 

[Bilbo]

Did you use sulfuric acid as well as phosphoric acid?

 

[Sublime Rasta]

No I put sulfuric acid in 1 glass and phosphoric acid in the other.

 

[Bilbo]

No real clue tbh but it would be worth checking with your water company to see if they add fluoride and chlorine to the tap water?

 

[Sublime Rasta]

I checked the water quality report and the water contains both chlorine and fluoride. That is why the pH increases?

 

[Bilbo]

You'd need to ask a chemist about that combination I'm afraid.
Stand the water in an open container for a couple of days to get rid of the chlorine but wtf the fluoride does or how to get rid of it I have no clue!

 

[pop22]

I moved, and I am now using city water instead of well water. In 24 hours I spike from 5.5 to 7.2. I have tried general hydroponics pH down and sulfuric acid. Both rapidly increase over a 24 hour period. At first I thought maybe I didn't soak my growing media long enough, so I put two glasses of water under my sink for 24 hours with a pH of 5.8. The same exact pH spiking occurred. What is my problem?

Youy need to find out if your water has chlorine, or chloramine in it. If its just chlorine you need to let the water stand in an open bucket for 24 hours, or set the buxket outside in a sunny spot And the chlorine will be gone in 3-4 hours. Then adjust the ph of the water, it will stay stable longer once the chlorine4 is gone. If you water has chloramine your going to have more work cut out for you. do a search here on that subject.

 

[Sublime Rasta]

I filtered my tap water with a brita filter, and the pH spiking does not occur. I will also try letting the water stand for 24 hours for chlorine evaporation. I have also invested in a 200 GPD reverse osmosis system because I really feel my tap water is an issue. I will update this thread with my findings to help anyone that may run into this issue. Thanks again for the help Bilbo and Pop.

 

[MadDoctor]

RO osmosis filters are the way to go, good move there.
I think many RO filters have a pre-filter stage that is supposed to remove the chlorine.
I use a nute tank for my soil grows that is exactly comparable to a hydro setup as it is PH corrected and has an air pump constantly turned on in it, my PH stabilizes in a few hours after I put the new water in, going up a little bit (+0.2-0.3) as the water absorbs the maximum amount of Oxygen it can.