HYDRO PH jumping up daily

[PLreef]

Question for the hydro pros. I set up a 5 gal DWC to grow out an auto in. I'm using General Hydroponics Flora series nutes and PH up and down.
I set my PH at 5.8 and when I check the next day the PH jumps up over 7.4. This has been going on daily since I started it 4 days ago. Can't for the life of me figure it out. Any thoughts?

[Smoklahoma]

I don't know why it does it? I change nutes weekly, because I don't know enough yet to guess at it. Before I got the dosers, I added ph down every 12 hours. My water starts at 7.1, it would always try to creep back up. Seams I would add down for about 4 days. Then it would kinda level off. When I didn't change nutes every week, after about 8 days I had to start using up daily.

[Tersky]

Hydro is a constant battle IMO. I started with hydro but now do coco exclusively cause its close to hydro but without the res issues.To answer your question tho, it could be many things.

First off do you use tap or RO/distilled water? RO water is hard to keep stable because there is no minerals to act as a ph buffer so i found that straight RO water fluctuated drastically. On the flip side, sometimes tap water is impossible to bring ph down i have found. I had to switch to RO/tap water mix as straight tap water would not go lower than 7. Almost like something the city started adding to the water was making it extremely difficult near impossible to keep my res in the proper range.

Second, are you measuring ppms? i found it imperative to measure ppms doing hydro cause it would help me diagnose issues. For example, i would measure ppms every res change to get starting ppm of nute mix. Then i would measure ppms every time i did ph checks. If i noticed the ppms going up while the water went down quickly then i was feeding too much and could adjust. If the ppms went down but the water didnt change much then i may need to feed more. I remember seeing a chart explaining the relationship between pH, ppm and water level but i dont remember where i saw it.

Third, check for algae or contaminates that could be causing ph to spike. If it is a new system did you clean the system before using? Not always necessary but a lot of times freshly manufactured and packaged items have thin layers of chemicals that can contaminate your system. As a rule of thumb, i cleaned all my new hydro materials with rubbing alcohol and rinsed and dried before using just to be safe. Could just be me being paranoid but hydro systems have to be clean and contaminate free or else whatever is in your res or water gets absorbed by the plant.

Lastly, do you have overactive air stones or lots of moving water? In my experience water agitation will raise pH levels if you have too many air stones or too much water agitation.

[PLreef]

Thanks for the response Tersky .
I'm using tap water that comes from a well. We do have slightly hard water here.
When I first mixed my nutes it was at 290ppm and it did rise to 300ppm. I was figuring that was from the clay pebbles in the water. Not sure though?? When I set up the system I throughly washed each piece.
As for the overactive air stone. I'm really not sure if mine is considered overactive or not. I have one pump that I connected both outlets into one using a Y fitting. It does bubble like crazy but I have nothing to reference it to. If I had to guess this one seems like the most logical. I had a suspension that this might be it. I can regulate the outflow of bubbles. Today I'll dial them back and continue to monitor the PH and see where it goes.
Hopefully I can get to the bottom of this.

[DW2]

Howdy PLreef, The pH will change due to the plants uptake of the nutrients in the water as they grow. When the water / nutrient mix is balanced (6.0 pH or there about) before it is given to the plants, it will go up in pH as the nutrients are use, leaving a some what lesser concentration in the reservoir. My set up (a Bubble phonics style) will go from 6.0 to as much as 6.5 in a week (depending on the growth stage). This is normal and nothing to worry about unless it get grossly out of range. I do not 'chase' the pH up or down during the weekly feeding cycle, just balance the feed and top off water (at mid week) at 6.0 and let them do their thing. Several grows back, before I figured (actually read and learned) this out, I nearly killed off several of my plants (pH shock can lead to nutrient lock!!) and ,now, I just balance the initial feed or top off and enjoy the ride.

[PLreef]

I understand what your saying about the plant feeding off the water and raising the PH. Unfortunately I don't think that's the case here. The plant is just a few day old seedling and the PH jumps from 5.8 to 7.4 in under 20 hours. It doesn't have much of a root system yet. Just a couple roots sticking out of the rapid rooter.

[DW2]

PLreef, I have seen the biggest changes in the pH during the veg stage. Could the be some thing else, like some algae, growing in the reservoir? Just a thought, some thing must be changing the pH. Have You checked the output of the air stones, to see if they are bubbling correctly? Another idea, do You a pH meter/pen? Could it be in need of calibration or replacement?
Good luck on tracking down the problem.

[gbauto]

https://images.app.goo.gl/7TJpmLs5MbLXd9dD7

This has always helped me.
Although I run Jacks 3-2-1 now, I agree with dw2. When I used GH Flora it would always self buffer down to 5.5 and then rise to 6.5 over the course of 10-14 days.
I'd then dump the system and repeat.

[Tersky]

That was the chart i was thinking of! Thanks for posting cause i couldnt find it.

[PLreef]

DW2 I just got a brand new Hanna Growline PH meter. I calibrated it with their PH solutions twice this week because I thought it might be the issue. I also checked it against my 4 other PH pens and they are all reading the same. This has got be stumped...
These reading were taken about 23 hours apart.

[DW2]

Hay PLreef, My mind must be fading in my old age. I remembered that when the totes (reservoirs) were new, it was difficult to maintain a steady pH in them. Over a couple of grows the totes became 'cured' and the pH began to become stable (other than the change from the nutrients being used). How old are the reservoirs that You are using? If they are relatively new, they should begin to stabilize with use. In the future, You could soak a new reservoir for 24 to 48 hours filled with a 50/50 mix of white vinegar and water to 'leach out' any residual chemicals left over from the manufacturing process, like mold release agents and other chemicals normally found in plastics.

[WillBlack]

This same thing has happened to me. I utilized one brand new reservoir for several grows and had this problem initially. Now that tub has been "seasoned" and the pH remains within range between changes. I just started using a second reservoir which has only been used once and I'm having this same problem again with that tub. It just might be that your issue is your equipment still has residual chemicals from the manufacturer leeching into your water. DW2 is probably completely correct.

[Jebidiah]

I don’t know if this helps but it seems when I recirculate the water through the net pots the pH always seems to climb over 7 after I have roots established I stop recirculating (remove the pump completely) and the pH maintains.

[PLreef]

Last night around 1030pm I re set my PH down to 5.75 and by this time I checked this morning (7 hours later) it was back to 7.3... I got nothing...

[Phlash]

Out of curiosity what is your tap water’s pH and tds untreated?

[PLreef]

Phlash

[Phlash]

PLreef First off I’m not a hydrogrower, I’ve only read up on it thinking about future grows and what would be entailed, so just throwing out a couple of thoughts. I’m sure you know these things but sometimes it helps to just talk through a situation.

To start aeration and turbulence in water will cause water to offgas aqueous CO2 which in turn increases pH so keep that in mind. Be sure to wash your hydroton well and use a pH’d (5.3-5.8) water to do so. pH the water for your reservoir first, let sit, then add nutrients and then pH adjust again.

Your tap water readings are extremely close to what mine are and has been part of my hesitancy to transition to hydro due to cost of filtration as it seems RO is almost a requirement of the method, then maintaining res temp being another potential cost hurdle. I’ll definitely be watching to see how your situation resolves.

[PLreef]

I think I figured it out.... it was my water temp. I added frozen water bottles and got the temp down around 65°f to 68°f and my ph only went up .10. Ill continue to monitor it but I believe this was the culprit. Thank you for all the advice.

[Phlash]

Great news! Thanks for the follow up

[PLreef]

Ph has been stable for the last few days. This hydro stuff is kinda fun. Here's my little hydro auto. I think she's coming along nicely.

[Phlash]

Nice, how are you maintaining water temps? Frozen water bottle changes?

[PLreef]

Exactly. I have to change out the bottles 3 times a day. Kind of a pain in the ass but I'm gonna continue like this through this grow. Haven't decided if I like this style of growing yet. If I do I'll buy a chiller for the next grow