Ph Consistently Rising?

i've been dealing with pH problems in my reservoir.
it's 14 gallons, using tap water, advanced nutrients (bloom a and b), usually pH down (keep it set between 5.6-5.8 pH) and a bit of h2o2.

res changes about every three days.

lately though, i've noticed a consistently high pH level.
i can set the pH to 5.6 and within two hours it's up past 6.1

i had a Hanna meter and calibrate every week. as of 3 days ago i bought another pH meter to verify and it shows the same; rising pH.

this has only been happening in our flower side res. for about 2 weeks but i feel it's already had a negative impact (phosphorus deficiency it appears due to nutrient lockout from the high pH)

what can i do to keep the pH steady?!




also, i've been considering a 24/7 pH and ppm meter. anyone have any advice or using a Control Wizard 24 hr meter?
man, it'd be nice to have a 24 hour meter that could automatically notify me via email when the pH or ppm's are off.

Depends on alot of things. First how big is yoru grow? do you have many plants? From your res size you you prolly have about a 400W. Another thing is what is your PPMs of your tap water. Is the tap acidic or basic? are you adding silica( acts as a base). Are you oxygenating the water? all these things can swing yoru pH. Just do what you hav been doing, set your pH at round 5.55 and let it rise on its own, then bring it back down. Eventually it will sit somewhere in the middle. after a res change check it like 3 times that day it should taper off.

Curious to know if your ppm's are dropping in between your top-ups...? If that's the case... normal... plants eat up some nutes, changing the overall chemistry, raising the pH... as they deplete the nute salts.


It never is stable... the pH... it's an active/living system that is always in flux. The goal is to stay within a range...

great advice! thanks!