Ph drift in DWC Bucket

Indoor Growing Hydroponics
#1

So what would cause a Ph drift from 6.2 to 6.5 twice in 24 hours? ppm 70, Temp is a steady 75, no other fluctuations. 13 Gal DWC CCh2O

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#2

It’s normal. If there are any dissolved gasses in the water the pH will rise as they leave.

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#3

Thanks, according to my feeding chart, Im supposed to be at a steady 6.3 for the first 2 weeks. That s going to be a bitch to stay on top of. Still new to this and Im still getting acquainted with how many drops of Ph down to dose and not overshoot. From what I understand, its not cool to do Ph Up and Ph down in the same water.

#4

maybe you could try using RO water instead of tap water. there’s also a line of nutrients called ph perfect which is designed to prevent drift but it may require RO water, i’m not sure

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#5

I find quite a lot of drift in my DWC’s, the way I counter it is I use a root zone conditioner, seems to keep the PH on point, so much I don’t check the PH at any point besides changing the nutes out :wink: I even top up the reservoirs with plain water all week and stays spot on lol

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#6

Im trying out Atami awa dwc specific line…it works well as per ph balance and buffer…
Ds

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#7

Also make sure you are using a good strong ph buffer, not a citric acid based product :wink: I literally add drops to adjust the reservoir.

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#8

I am using RO, 0ppm @ Ph 8

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#9

Same here, it only takes a drop or 2 and I use UC ROOTS from Current Culture. The whole point the their nute line up is that it doesnt cause Ph drift.

The only thing I can suspect is that my Ph down & up maybe contaminated. Since I have 1 Gal bottles, I decided to decant into smaller glass jars and I use a syringe to take out what I need and squirt back what I dont use, THAT could be my problem but I was hoping someone could verify that for me.

#10

PH drift is normal over a couple tenths of a point. Your shooting for a PH range between

max low of 5.2 to max high 6.5
with your sweet spot hitting
Between 5.5 and 6.2

If there was any one number I would settle on would be PH 5.8 as this opens up lots of nutrient uptake ranges.

Yes you can grow at PH 6.3, however I would start at 5.5 and let it drift up to 6.3 to allow for maximum nute uptake bandwidth. Using a range rather that a static PH level

Edit: This is an old text book picture…there is a new one with a little be more accurate ranges but I don’t seem to have it…Maybe someone else might
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#11

I don’t know if you will be able to totally stabilize your ph, but if you shoot for a range you should have nothing to worry about. You can buy a lot of products that claim this and that. I do dtw hydro and usually adjust my reservoir to between 5.6-5.8 when i refill. It will drift up to 6.2-6.5 before it needs to be refilled. Sometimes I’ll readjust the ph or top up, but it works fine with the drift.

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#12

The only way i can think of to eliminate the drift completely would be to boil your water first. That would probably drive of any dissolved co2 (carbolic acid when in solution).

Or set up a system with peristaltic pumps and a controller.

#13

It’s the water not there nutes that are causing the drift.

#14

One of the down falls of DWC is the wild swings you can get in PH over a short time period…
Things like water temps… water/nutreint up take by the plant…plant size…room temp… bubbling the water with air pumps all can effect PH over a 24 hour period for sure… I keep a 40 gallon reservoir for my flowering plants I look for a nice slow swing through the ph range over a 12 to 14 day period… I’m able to do this by topping off the water in the reservoir daily… I’ve installed an auto top off for my system that does this for me daily after the plants have been feed/watered each day.

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#15

This. If you added both like 1 - 2 days before this drift (or at the first “correction”) here is your problem. I not even have pH+ anymore. If the pH start to swing down I change about 20% of the reservoir with non-corrected pH water (my tap water is 7.4). This usually is enough to buffer the water back to a desirable range.

If you just filled your reservoir, sometimes the water float up in the first days until it buffers at your desireable range. This is super common.

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#16

my water starts at 8 and I Ph down after adding Nutes, the drift is always upwards. If I ph down too much, I dump the water rather than Ph it back up.

For now, Im just messing aroound with a 13 Gal Bucket, then I will move up to a 34Gal tub with 6 pots and eventually set up the 2 X( 8 bucket RDWC )systems which will each have their own reservoir and chillers. If there is a learning curve and mistakes to make, its now so I dont screw up when I go BIG, lol

#17

Perfect man !
Remember that even with dump water -> try again you are adding more un-buffered water to the mix, so expect a bit of fluctuation up.

I admire your patience. Anything between 5,6 and 6,5 will not hurt in veg normally. Let it float a little, experiment with less pH-.

#18

thanks man. Do you mean I could adjust the dumped water after a couple of days? That would be nice, filtering water is a bitch and I hate wasting it.

#19

Was not what I was meaning, I am bad at this - sorry.

What I was trying to mean when I said “dump water -> try again” was that when you remove some water from your reservoir and top with “new water” this “new water” (even if pH corrected) is unbuffered and will help to float your pH up.

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