DWC PH dropping question

[BudMasterzero]

So I am on my 3rd week of flower. I have noticed that I am PH'ing my tub each day.

It goes from 5.8 to 5.4 (not to much lower if any)

With out changing out my water is their some way to combat this? I read (correct me if I am wrong) that this has something to do either with nutrient uptake or root issue.

Right now I am going to calibrate my meter. I mean she looks fucking happy as hell. If I could figure a good way to shrink my pictures I would post some of this scrogged out beauty.

 

[Zen Master]

My nutes have a pH buffer that lowers pH. As in the more nutes in the solution, the lower the pH (before adjusting).

if your pH is dropping it means the plant is consuming more water than nutrients, thus increasing the relative nutrient % in comparison to remaining water.

how big is your bucket/reservoir? the smaller it is, the faster your pH will swing.

 

[superusa]

[/U]aster;4421727]My nutes have a pH buffer that lowers pH. As in the more nutes in the solution, the lower the pH (before adjusting).

if your pH is dropping it means the plant is consuming more water than nutrients, thus increasing the relative nutrient % in comparison to remaining water.

how big is your bucket/reservoir? the smaller it is, the faster your pH will swing.

Word... OP try diluting your nutes some (reduce ec/tds/ppm).

 

[BudMasterzero]

Yeah I am going to do the dilution right now. I got a 15 gallon tub under a 400.

Also I am going to get my water checked soon since my meter is acting funky.

 

[Zen Master]

Yeah I am going to do the dilution right now. I got a 15 gallon tub under a 400.

Also I am going to get my water checked soon since my meter is acting funky.

pick up one of the cheapo drop pH testers too if ya can. If you dont store properly/calibrate the e-meter religiously its a crapshoot. I've lost a whole crop because the pH was stupid off yet it still registered 5.8.

hell I dont even use my old e-meter, all I use are the drops.

 

[BudMasterzero]

I am noticing that my ppm meter goes ape shit when the power goes off and on. Also it doesn't seem to like being near the heater.

good news though, I got a drop t ester. edit....my drop test looks to be between 5.0 and 6.0

diluting my water instantly raised my ph to 5.7 but now it says my ppm are 1400. So I am bubbling a new batch of water. Must have had a bad bottle of nutes or added too much.

edit edit: I may have found a problem. I went through my nutes to make sure they weren't all clumpy. Well all were except my liquid karma. The bottom was like jello. I guess when it breaks down in water is raises and lowers everything..

 

[FreezerBoy]

Because nutes are acidic, EC and pH move in opposite directions. The first possibility is pH is dropping due to over feeding. When you drink more water than nutes, nutes build up and pH drops. Try lowering feed levels and see what happens.

Remember that bottle and feed chart recommendations are not based on plant health but on getting you to use nutes asap so you buy more than you need.

 

[Stagetek]

Rough rule of thumb is:

• pH drop with nute strength increase; back off on nutes
• pH rise with nute strength decrease; plants want more nutes
• solution in res drops with pH and nute strength stable; it's a good thing

I have a similar issue but while pH drops, solution strength (EC, PPM, TDS) stays stable. In my 2 current grows, at least, there is no difference in pH swing regardless of whether or not I use a pH buffered version of base nutes. A few years back I had similar issues using tap water; so I doubt that RO water is my cause. Strains are dissimilar as well.Like you, my plants look healthy; but I'm constantly waiting for the other shoe to drop.

Are you using any silica products? Some have postulated that potassium silicate can cause pH swings.

 

[BudMasterzero]

to FreezerBoy - I agree with it being over nuting. I am not getting burns yet or anything like that, but that is what I want to avoid.

Hey any easy way to get a bit o nitrogen into my system without having to add a bit of grow in?

Are you using any silica products? Nope none that I know of.

 

[FreezerBoy]

What nutes are you using? Nitrogen is a big reason for veg (1:1) and flower (1:2) formulas. Flowering plants just don't need that much. I'm not aware of any nutes that are strictly N or P or K (though that doesn't mean they're not out there)

Without being gross, you could always piss in the res.

 

[Stagetek]

...

if your pH is dropping it means the plant is consuming more water than nutrients, thus increasing the relative nutrient % in comparison to remaining water.

...

Wish that were so; both my flowering RDWC grows have pH dropping like a rock and swinging by over 1.0, daily, with little or no change in the solution strength. There are more details here:

https://www.icmag.com/ic/showthread.php?t=211503

This is one of those things that seems to continually crop up in DWC related threads. Root zone issues or silica supplementation are 2 of the more common possible causes mentioned; both of which are related to nutrient solution composition. It's a dance, started many times, that I have yet to see brought to a satisfactory conclusion. Happens regardless of whether tap water or RO water is used; and, and with or without the use pH buffered base nutes.

While many growers successfully bring in grows with fluctuating pH; it is far from a given. The fact that it really does not seem to manifest until well into flower just causes more stress, as there is more to lose.

What do the tree mavens have to say about this topic, given that most such grows are done in DWC variants? Are these swings just part of DWC grows, that can be dealt with by large infusions of pH UP; or, is this just a band-aid solution, as likely to add to the problem as it is to remedy it? If such swings are caused by the starchs and sugars in bloom boosters and sweeteners, are there similar, non-organic supplements that can co-exist with H2O2? Do these additives reliably increase yield enough to justify using them in DWC?

 

[Zen Master]

you shouldn't be using foamy organics in a DWC, at least in my opinion (and if you dont like cleaning floors).

you'll be bubbling a whole colony of bacteria/fungus that could be beneficial, but I rarely see it work out for people with DWC. Most end up saying screw the organics and go with much less bottles of nutes/supplements and even go so far as to add h202 or bleach regularly.

silica causes pH to rise, I use it in place of pH up actually up until week two-three(ish) of bloom depending on strain.


if you can afford to try it out, go get a small bottle of Gen Hydro's Micro and Bloom.

use at 6/9 mL per gallon respectively (no need for floraGrow at all) and bam, super simple DWC friendly nutes that cost 1/10th of AN. Dont add a whole bunch of other stuff (humics and fulvics specifically) and I bet your pH will stabilize.

Keep It Simple Stoners.

 

[ranta]

in flovering period ph always drops , just add a little water dont add ph up

 

[Stagetek]

in flovering period ph always drops , just add a little water dont add ph up

That's oversimplistic and will only work if the solution strength increases while pH drops. Even then, it's questionable whether the addition of water alone will cover the drop, as nutes are not depleted at the same rate. The further from change-out the greater the ratio shift.

 

[BudMasterzero]

Hey FreezerBoy. I use pureblendpro grow and bloom, liquid karma, mag cal, and at the start of the flowering period big up (already switched it to a new batch minus big up).

Currently the solution for me is to add about 2 more gallons to my rez. Seems to stabilize it so no more bouncy ph.

 

[John LOQUE]

For me, if the PH rises while EC drops, it means that the plants are eating the food i give them, everything is find, when the ph stops rising, generally ec is low, and i change the nutes. Generally, at the end of the flowering cycle, the plants want no food at all, and ph drops even with plain water, while ec rises a little, it the flushing cycle.
I start with a PH 7 water, i put acid to lower it to 6, and every day i find the ph at 7.5 while the ec has dropped. I lower it to 6 and so on during a week or so. They also drink a lot of water.
It's not so simple as saying it's because the nutes are acidic and when there are less nutes in the solution the PH rises...There are chimical reactions in the roots area that i ignore but which change the PH.
So PH rising is a good sign of growth IMHO

 

[ranta]

That's oversimplistic and will only work if the solution strength increases while pH drops. Even then, it's questionable whether the addition of water alone will cover the drop, as nutes are not depleted at the same rate. The further from change-out the greater the ratio shift.

Stagetek simplisity always works
as i said in flowering period ph always drops in dwc , than you just add an amount of water or water with nutes if needed to corect ph ,usualy the amount of water thats added when corecting ph is almost the same as the amount of water consumed by plants ...

 

[BudMasterzero]

Good thread here. I know of many people who do dwc that struggle with ph fluctuation.

 

[Stagetek]

Ranta, take a look at my thread and you'll see I'm getting daily swings of 1.0 or greater; adding water alone will raise pH from 4.7 to 4.9, maybe even 5.0, for all of the 3 minutes or so that it takes for the pump to send the res contents into the buckets. While water alone may work for small fluctuations, more is required in some set-ups; as BudMasterzero points out, this is a recurring comment in DWC systems.

Possible causes can be as simple as sizing a res too small for the plants, and range through water issues to strains that feed disproportionally heavy on 1 nute or family of nutes. The source of nutes, such as potassium silicate, is also stated as a contributing factor. Then there are rootzone issues such as the chemical interaction of roots and nutes; or, root rot.

These are some of the key points in the discussions regarding stand-alone DWC v RDWC; or running beneficials v sterile solutions. Given that most of the growers who routinely grow trees seem to run variants of DWC, those of us who want or need to get as much weight as possible, from a limited number of plants, look at this as a viable option. Learning how to do so, without accepting the inevitability of losing a crop, is the trick. It's only by gaining knowledge of all the variables involved, that we increase our yields and success rates.

 

[thinkin]

The PH problem is FIXED!

The PH problem is FIXED!

My mysterious PH dropping problem is GONE!

Last week or two in bloom.

Definitely wasnt typical over/under nutes PH swing problem.

Twice a day, i have been adding slightly larger amount of H2O2.
Not sure what happened. Maybe I over did it?
Within 12 hours PH went from 6.0 to 11.00 !
(readings from 2 ph meters and drips)

Girls were not showing signs of stress yet..

Immediately dumped the rez for fresh nutes.
with No H2O2 added. Ph 5.9

Small chance, I may have messed up an added "PH up" by mistake. no way to confirm. doesnt seem likely.

36 hours later and no H2O2. Ph is solid!
no more (normal) 1.0 swing within 12 hours!

Weird problem + Weird solution = still confused.

conclude:
Brief PH spike didnt hurt the plants like i thought it would.
Either excessive H2O2 or too much PH up caused the PH spike.

BUT Ph swing is gone!