Constantly changing ph

So i have started to notice that water i use for my clones is changing ph every day. I use normal hydro PH down (not vinegar or anything wierd) and i let my water sit for 24hrs before PH'ing. Once i PH the water i let it sit for another couple hours then retest and if it is not in a good range, PH it again and let it sit again. Recently i started some new seeds and i started testing the water in my spray bottle every day. It seems the PH goes up each day by almost 1 point. Why is this? Is this normal? I plan on doing an experiment on all this using a control bucket of water, boiled water, bottled water, and maybe some RO water if i can find it. I don't know why PH would change if all the chlorine has evaporated and the water is just sitting. I'm not mixing anything with it that could slowly break down so why the change? I am afraid the water in my rock wool for the clones is swinging the same way which is undesirable obviously. Anyone got any ideas/suggestions? Also, i have a hanna PH pen recently calibrated and i tried testing the water with friends pen with the same conclusion.

you need to calibrate your PH pen everydayand keep the tip moist at all times. i have seen it sugested to use a small piece of brand new sponge inside the pen cap to hold moisture for the tip. if all of those things are covered i dont know what to say about plain water in a spray bottle having PH swings like that

my ph is changing like that too. im using flora and it seems like every 4-5 hours mine goes from around 6-6.5 to 7 sometimes if i leave it too long itll get up to 8 any advice. im using a bubble bucket right now

I had the same problem with bubble buckets/water farms. After fighting the PH swings and root rot for years, I finally listened to Lucas, and went with a big rez that feed the buckets. The bigger the rez, the more stable, plus air. My veg rez is 25 gals, and has very small PH changes. the real solution to my problem was getting an RO unit. It removes the lime, salts, and whatever - no more problems with PH swings. Do your temps change a lot during the day?

I have the same problem so I just switched to distilled. I never have any problems maintaining ph with GH nutes using distilled. I think it depends on the alkalinity of your tapwater wherever you live.

I googled my local water quality report and found there to be a high amount of calcium carbonate, which I think would explain why the ph of my tapwater constantly wants to climb. CaCO3 is the principal cause of hard water in North America. It is also widely used as a stomach antacid (Tums) because of its ability to alkalize acids.


Although when I mentioned this to the "I've only been doing this for ten years guy" at my local hydro shop, he informed me that our municipal water was perfectly suited for hydroponics. So maybe I'm wrong.

PH is going to swing, based on the environment. When a plant feeds, the water that delivered the nutrients tends to go up in PH. If a plant is overfed, the ph will go down. Temperature also affects PH readings.

The post above that claims one PH point per hour is ridiculous. in 8 hours it would be off the scale if that were true. If you are hydro gardening, worry more about ppm than ph. The PH will take care of itself if the PPM is carefully monitored and adjusted as needed.

Serapis said:

PH is going to swing, based on the environment. When a plant feeds, the water that delivered the nutrients tends to go up in PH. If a plant is overfed, the ph will go down. Temperature also affects PH readings.

The post above that claims one PH point per hour is ridiculous. in 8 hours it would be off the scale if that were true. If you are hydro gardening, worry more about ppm than ph. The PH will take care of itself if the PPM is carefully monitored and adjusted as needed.

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The claim is not ridiculous, I have the same problem with my tapwater.

Its not really a problem its just how plants feed and drop stuff as they grow it causes PH to swing. Yes your environment can play a factor but for the most part I dont adjust my PH except when i first do the nutes at the beginning of each week. As long as my PH stays between 5.6-6.2 I really dont care I let the plants decide. I also Flush for few hours twice a month though and have RO system that tops off my reservoirs throughout the week. Chasing PH too much is bad for your plants because too much PH up or PH Down can add to salt build up and lead to nutrient lock which leads to root rot.

P.S. C. Morbuds I always run air stones in my reservoirs to aerate roots properly and have no problems. Also reversing flow on the hydrofarm/grower system each week helps even the nutrient and air flow to the plants. I have heard about people running Medical Grade oxygen to there Airstones and it makes the roots go crazy growth.

Best of Luck
https://www.rollitup.org/grow-journals/384835-swiftgrow-journal.html

My tapwater's ph will constantly climb upwards at a very fast rate no matter how much ph down I use. This happens with or without it coming into contact with plants or anything else for that matter. Its something in the water, plain and simple. The only solution is to use distilled/RO water.