Why would my PH keep creeping up.
Bananna Kush
Week 3
Last PH check was 6.8 3/10/25
Prior PH on 3/5/25 was 7.1 and using PH down i brought it back to 5.8
PPM 600
Temp 70
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How much solution is present in your grow space? The more liquid reserve you have will slow the PH climb. Small quantities of liquid in a DWC will move fairly quickly and generally up. Adding a standing reservoir with some capacity is the best way to solve this.
Do you have a chiller? Temperatures above recommended can also cause PH problems.
Having a higher salt concentration in your mix will help too.
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@UncleFester I had this problem in a 5 gallon bucket with Lotus Nutrients powder mix. I switched to Advanced Nutrients pH perfect and now I never have a pH problem in any of my buckets or tote.
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Ph maintenance is normal in dwc system as the air alone will cause it to rise. Like Myfriendis410 said smaller your res is the faster it will happen. I wouldn’t let it get to 7 either. If you see it creeping above 6 is time to reset. Go a little lower than 5.8 if you need to.
In a smallish res I would expect to have to adjust this daily. In 20+ gallons maybe more like couple times per week if everything else is good.
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When I was using Lotus in my 5 gallon bucket I had to adjust pH every other day, using this I don’t adjust or even mess with pH but 2x a week going in an out.
I’ve tested during veg going in and it’s 5.7 and out is 6.2.
Flower 5.7 in 6.5 out.
They are acceptable flux ranges
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My res is 7 gallon with 5 gallons of actual water. I have a 9 gallon and may switch before the roots get out of control. I’m doing a total res switchout every two weeks, i’ve read that somepeople never do a switch/ clean is this recomended.
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The first 3-4 weeks you don’t have to do a res change, that’s the time the plant is making it’s bacteria on the roots to stay healthy just keep topping off until about week 4 then res change an rinse out res.
Then in my 5 gallon bucket I change it every 7 days I wouldn’t go longer then 10 days without changing the res.
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There is no one way that will fit anyone. Some people will be able to maintain a res with top offs and not need to run a complete change and others will have to do it multiple times per week. You need to maintain proper ph and reasonable nutrient solution concentration, however it takes. If your res numbers look good then less is needed. But if they’re all over the place you’re not going to be very successful addressing it on a 2 week basis.
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Thanks!!
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If you use water that contains a lot of minerals (mainly calcium), the pH can go up over time due to the calcium carbonate in the water.
If your tap water has a lot of carbon dioxide in or the other gasses have been driven out of the water (due to being under pressure in the pipes), the pH will normally go up over a 24-48 hour period after you fill the container with the tap water. This is due to the gasses (nitrogen, oxygen & carbon dioxide) getting back into the water in their normal levels and balancing the pH.
Your pH meter might be dirty and or need calibrating.
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From experience my tap water starts at 7 it takes 3 times phing it down over the course of 3 days before it will balance out, when setting up a new grow.
I found after week four of growth it stays stable around 6 even after a flush and phing once. I assume the root ball helps balance the ph.
I also find that 3rd week of flower pH will start slowly dropping. What I found is if my ppm rise my pH drops and and if ppm drops my pH goes up during flower.
Like other comments say gradual pH change is normal large change I am looking for culprit.
I flush my system based on ppm when it starts climbing without adding nutrients means the plants are not eating, and will possibly cause nutrients locked out.
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Do you have any containers you could fill up and cycle the water for a few days?
This is what I mean, I just did a full change out on all the res and then went an made another 20 gallons of mix waiting with air stones in it running.
Will use this to top off and refill res next change.
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Hello,
Yes i have another res that i use now that she’s taken off, the PH has stabilized this past week to 5.8, i’ve read on here that some people never clean/ change out the res, i’m not running an external secondary res, i’m on a two week clean/ change schedule,
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I change mine based on ppm example my base nutrients is say 900 when I add, and when it climbs 1800 ppm tells me the water is getting a build up of stuff the plant is not consuming. So I flush and start over. That generally happens 3 times a grow.
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