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water My Tap water ph is 9.0, is this ok?

Jeffcontonio

Extreme Member
I hadn't put much thought into the quality of the tap water I water my plants with until just recently. I did a ph test and it came back high, 8.98. Is this acceptable or should I adjust it closer to 6.8-7.0?


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That's really high in fact, i think it could cause nutrient lock up in potted peppers. In ground plants might be able to adjust somewhat but you will do much better getting it down between 6.5-7.0 IMO
 
hogleg said:
That's really high in fact, i think it could cause nutrient lock up in potted peppers. In ground plants might be able to adjust somewhat but you will do much better getting it down between 6.5-7.0 IMO
Agreed.

I have a 200L drum that I fill with tap water (when it's not raining) and use PH DOWN to adjust to 6.5 then use that to water my potted plants.

The improvement since doing so has increased my yield 10X with same number of plants.
 
Jeffcontonio said:
I have some ph down however I don't see a doseage chart. How much ph down per gallon should I begin with?
 
I don't recommend guesstimating like that. Even if its just litmus paper do proper testing to get your formula right then you'll know the ratio.
 
I like the gh ph test kit better than most cheapo digital testers.
 
GH-pH-Test-Kit.jpg
 
Given that ph uses a logarithmic scale with base 10, a ph of 9 is increabibly high compared to 6.5 to 6.8. We're talking over 150 times the number of free H ions at a ph of 6.8.
 

Jeffcontonio

Extreme Member
I'm getting different ph readings from the hot tap vrs the cold tap even when water is left at room temperature. Does that make sense?

The hot tap is much higher in ph compared to the cold. My cold is still high, 7.8, but not as bad as the hot tap that reads closer to 8.9.
 
How are you measuring your pH? I don't think it would change with temperature. Cooling or heating the water wouldn't change the pH. 
pH of 9 is pretty basic, that's on par with baking soda. 
 

Jeffcontonio

Extreme Member
I have the old school hot water heater in the basement . I have to run it a bit for it to actually warm up. It was tested while still cool.
 
Jeffcontonio said:
I have some ph down however I don't see a doseage chart. How much ph down per gallon should I begin with?
You can add a few drops at a time to a large vessel and stir, then re test until you have the right PH. Even if you had the dosage chart you would still have to test to make sure it's right before giving it to your plants anyway.

Based on my experience I would start with one drop per two gallons at the most..
 
Reducing the pH from 9 to 7 will cause a lot of salts to be created and it will likely not be good for your plants or soil
I would look into distilling the water or using RO
 
Powelly said:
Reducing the pH from 9 to 7 will cause a lot of salts to be created and it will likely not be good for your plants or soil
I would look into distilling the water or using RO
Been using PH down (phosphoric acid) in the same pots for over a year.. no problems. In fact my pots are thriving with a range of fungi and plenty of worms breaking down the old leaves and mulch.

It only requires 4-5 millilitres in 200 litres of water to bring my PH from 8+ to 6.5... so when you think about the minuscule amount of PH down that actually ends up in each pot (30L pots) given they get only 1 litre each per day in only in the height of summer I doubt there would be much in the way of salt buildup.
 
Jeffcontonio said:
I'm getting different ph readings from the hot tap vrs the cold tap even when water is left at room temperature. Does that make sense?

The hot tap is much higher in ph compared to the cold. My cold is still high, 7.8, but not as bad as the hot tap that reads closer to 8.9.
 
Listen me, real chemist here.
 
If you use pH meter, it is basicly a voltmeter. It measures voltage and converts it to pH by this:
 
[SIZE=12pt]U= -0,059pH + k[/SIZE]
 
Voltage is dependent on temperature! If you use pH meter for hot water, it is usually calibrated for 25°C and you get fake results. Use it only for sample at approximately 25°C to get trustworthy results.
_____________________________________________________________
 
I have done dozens of tap water analysis and 9,0 pH seems like bullshit. Absolutely pure water would have 7,0 pH, distilled is usually acidic due to carbon dioxide absorbtion and tap water is usually 7,5-8 pH. I don't see problem with 7,8 water. Just adjust it with little bit of pH down for hydro.
 
PS: I hope this is understandable, I tried to make it as simple as possible but my english is bad anyway.
 
Jase4224 said:
Been using PH down (phosphoric acid) in the same pots for over a year.. no problems. In fact my pots are thriving with a range of fungi and plenty of worms breaking down the old leaves and mulch.

It only requires 4-5 millilitres in 200 litres of water to bring my PH from 8+ to 6.5... so when you think about the minuscule amount of PH down that actually ends up in each pot (30L pots) given they get only 1 litre each per day in only in the height of summer I doubt there would be much in the way of salt buildup.
 
Thanks 
 

Jeffcontonio

Extreme Member
My town does buffer the water to a goal of 7.5-8.0 (they say it's to help corrosion)

Is it possible I have mineral deposits in my hot water heater causing higher than normal readings on the warm side?

Keep in mind I am not testing it while hot. This is not a temperature issue.



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How long after it cools down to a room temperature do you test it?
If it is mineral deposit issue, letting the water sit to precipitate the base excess should bring pH back to normal.
 
I have never seen so high pH of tap water, it may be due to sodium hydroxide they add.
 

Jeffcontonio

Extreme Member
Neme said:
How long after it cools down to a room temperature do you test it?
If it is mineral deposit issue, letting the water sit to precipitate the base excess should bring pH back to normal.
 
I have never seen so high pH of tap water, it may be due to sodium hydroxide they add.
It was taken before it warmed up


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