ElkyBoy said:

Hi,
I have a problem with the PH of my water in my buckets..it’s always go up !. I explain: every time I set it up at 5.8, I check it 2 days later and it’s now 8.4 ...I really don’t understand, someone have an answer ?

i add my nutrient before fixing my ph.

thank you

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Kampbe1l said:

dissolved CO2 may be one reason for pH to change in standing water over time. temperature also would affect the pH reading. Not sure about hard water and its minerals/metals/etc. perhaps evaporation causes changes in composition of reservoir...but I will leave it to the scientists here to explain in layman's terms.

going off tangent, just an example - rain water, because it's carbonated by falling through atmosphere, it's more acidic, which explains also why many plants after rain has yellowing leaves, etc...

anyway, nutrients added to straight tap water, then this tap water de-chlorinates and other minerals reacts, and evaporation - all would change your pH reading over days.

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BigCube said:

I always fix my ph first. If you fix the ph of just your water, and it bounces back..
Your water has something in it messing with the buffering, or your ph down solution isnt very good.

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Smoking Gun said:

Are you using tap water or filtered water? If you are using tap water have you checked the ppm before you add any nutrients? Again if you are using tap water, do you let it sit out for a day or two before using it? You should be checking the pH of your water every day, you will catch the swings sooner.

If you are using filtered water try getting your water ready a day ahead of when you plant to fill your reservoir(s). By that I mean add some calcium (cal/mag will do) to the water 24 hours before adding any of the other nutrients. This will give the calcium time to impart itself into the water which will ultimately provide a buffer for when you do add nutrient.

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