pH RAPIDLY Climbing

The pH in my 3 gallon reservoir is climbing through the roof. I'm balancing it three times a day... The plants are three weeks into veg and they are very healthy... there are currently only three plants using that reservoir. I'm growing in hydroton medium and I just changed the water Monday. I'm balancing to 5.6 and it's climbing very quickly.

Last night was the most alarming. The pH went from 5.2 (I left it low because of the climbing) to 6.8 ... in about 12 hours ... It's now taking a SIGNIFICANT amount of pH Down to drop it to where it needs to be... I thought at first it might be the medium so I was giving it some time but the problem continues to escalate...

I've tried searching for every possible combination of pH and rising, climbing, going up, etc... to no avail, please help!

did you rinse out the hydroton before using it? I know that can affect it.

Yup I soaked it for 45 min then rinsed then soaked it in the grow water for another 10 min...

Is it possible it's caused by Algae? And if so, how can I get rid of it?

i don't think algae can cause that, but I'm not sure.... how bad is your algae problem? must be pretty bad.... I have some algae, but have no issues with ph fluctuation.

to get rid of algae, use a little h2o2 in your rez.

Sorry I'm not using hydroton and I have no idea why I typed that, I'm using Grodan ...

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sorry, I'm not sure what grodan is. and florida girl is right, the small res is playing a role in your issue as well. I'm surprised that you don't have to fill the water after a couple days. thats too much work IMO. what type of ph adjusting solution are you using? is it organic or no?

The res for blooming is 8 gallons so that will definitely help. Meters are cleaned and calibrated as of yesterday The pH down I'm using is General Hydroponics liquid... I need a larger bottle, hahahaha Seriously I'm having to put in like 5 mL plus per .1

I can't complain too much though as the plants are loving whatever is going on It's just alarming how fast it's going up... something has to be off... it might be time for a bleaching of the res.

Ok I'm 99% sure it's algae... the plants sit on top of the res which is solid black and very hard to see anything. I pulled up some of the airlines and they do indeed have algae on them... I'm using Voodoo Juice so I can't dump H202 in there... Guess I'll have to move the plants and clean everything out, get it nice and sterilized and then move the plants back into fresh nutes...

Anyone have a trick to doing this? Do I need to rinse the roots as well or should I soak them in pH balanced water or what? Any advice would be much appreciated and thanks to everyone who's helped so far!

Florida Girl said:

Nutrients affect the PH level. So as your babies are taking in the nutrients along with normal water evaporation your PH levels are going to climb.

Sounds like your babies are eating well to stay healthy. Just stay on top of that PH .... it's going to be work. You may want to get a bigger reservoir .... 3 gallons seems small. With a bigger reservoir you may be able to go longer without having to adjust PH.

Also... don't forget to clean and calibrate your meter

Click to expand...

Yep my res climbs daily as the plants use up the nutes too.
a good trick someone taught me is to get some limestone rocks from your garden supply store and after washing them off drop a couple into the tank.
wait a few hours and check PH again. after some trial and error you can get the PH to balance and stay right where you want it ( a pain at first I know but better than buying gallons of PH Down)
Heres what happens...
what the limestone will do in the solution is create a ph buffered solution that resists change.
A base (CO3) with its conjugate acid (HCO3) in a salt form (CaCO3-limestone) will naturally keep that ph at a constant.