DWC PH issues: Ph dropping like a rock - Please help

Those number look fine, relax and smoke a joint...give it a week to stabilize and see how things are. If things are still crazy try doubling your rez size as like I said larger volumes of water provide more buffer for ph stability. If you're still pulling your hair out but still want some of the benefits of hydro then try a hempy bucket. Things that you could really benefit from right now would be a larger volume of water, silica and patience as you seem to be doing every other thing correct. Also, know that if your plant is locked out due to all this stress it could take a week or two to see things turn around. A side not: I don't use it and think it's way over priced but there are nutes that are PH stabilizing by themselves. I think advanced makes PH Perfect with is auto stabilizing but I don't have any experience with it.

@taproot - As much as I would love to leave her be, I can't. I just took another PH reading and my PH is down to 5.7 from a high of 6.2 this morning. I expect the PH to drop even further to about 5.5 by the time lights go off at 7:00 p.m. tonight. And mark my words, when I check PH tomorrow morning, I will not be surprised if it's around 5.0.

I plan to go to my local hydro shop tomorrow in hopes they can shed some light on this.

Judging from today's photos of the plant, I would see she still looks pretty healthy overall, despite the wild PH swings that have been plaguing me for weeks now. It's all this crap going on in the reservoir that is really pissing me off.

John1961 said:

@taproot - As much as I would love to leave her be, I can't. I just took another PH reading and my PH is down to 5.7 from a high of 6.2 this morning. I expect the PH to drop even further to about 5.5 by the time lights go off at 7:00 p.m. tonight. And mark my words, when I check PH tomorrow morning, I will not be surprised if it's around 5.0.

I plan to go to my local hydro shop tomorrow in hopes they can shed some light on this.

Judging from today's photos of the plant, I would see she still looks pretty healthy overall, despite the wild PH swings that have been plaguing me for weeks now. It's all this crap going on in the reservoir that is really pissing me off.

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Not trying to sound rude but nobody is saying to ignore too low or high PH, what we're saying is stop dumping your tubs but continue to adjust as needed and hopefully things will equalize over several days. It took about five days for mine to get locked in but I also was using 12 gallon storage totes. You'll get there!

Thanks, @taproot . You are not being rude at all. This is my first time doing a DWC, and of course, I want everything to run perfectly. But it's obvious I have lots to learn so I welcome any and all input.

Interesting how you mention that it can take several days to dial in a reservoir. In my uneducated mind, I figure once I mix my soup up and set the PH, then I should be good to go.

But my understanding is that I should be seeing slight rises in my PH as days go by. I certainly should not be seeing huge drops in my PH the day after I drain / refill the reservoir and every day thereafter.

Isn't it unsafe or unhealthy for the plant to be adding so much PH-Up everyday? I mean, that stuff builds up in the reservoir, right? At what point do the levels become too much?

John1961 said:

Thanks, @taproot . You are not being rude at all. This is my first time doing a DWC, and of course, I want everything to run perfectly. But it's obvious I have lots to learn so I welcome any and all input.

Interesting how you mention that it can take several days to dial in a reservoir. In my uneducated mind, I figure once I mix my soup up and set the PH, then I should be good to go.

But my understanding is that I should be seeing slight rises in my PH as days go by. I certainly should not be seeing huge drops in my PH the day after I drain / refill the reservoir and every day thereafter.

Isn't it unsafe or unhealthy for the plant to be adding so much PH-Up everyday? I mean, that stuff builds up in the reservoir, right? At what point do the levels become too much?

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Dude. Just adjust it. Its not gonna build up, its potassium carbonate, the plant will just use it as a nutrient.

Whether it goes from 5.5 to 6.1 or 6.1 to 5.5 the plant is still making a full swing.

Just something I had.

Jypsy Dog said:

Just something I had.

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Thats a really good chart for hydro newbies!

Pretty much is spot on with what I suggested the issue was.

rkymtnman said:

i would ask both members who recently suggested to raise your feed way up, why is my ppm's going up and not down? neither one addressed that issue.

good luck @John1961

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I Believe your ppm can rise for a number of reasons including high temps, it all depends how fast it is going up and if the water level is dropping with the rise at a decent rate,
I try and have my ppm slowly rising and i mean slowly, a slow rise in ppm with nutrient levels going down shows they are getting what they need from the nutrients but a fast rise as you say is a big issue and needs addressing asap.
ppm going down means they need more and ppm not moving is desirable.

My ppm is currently going up from 930 to 1000 (tds) over a 2 to 3 day period and i have no issues at all no burn nothing, Now if this rise was happening over a 12 to 24 hour period i would reduce it to maybe 800 and monitor.

Peace Out and much respect rkymtnman!

neckpod said:

I Believe your ppm can rise for a number of reasons including high temps, it all depends how fast it is going up and if the water level is dropping with the rise at a decent rate,
I try and have my ppm slowly rising and i mean slowly, a slow rise in ppm with nutrient levels going down shows they are getting what they need from the nutrients but a fast rise as you say is a big issue and needs addressing asap.
ppm going down means they need more and ppm not moving is desirable.

My ppm is currently going up from 930 to 1000 (tds) over a 2 to 3 day period and i have no issues at all no burn nothing, Now if this rise was happening over a 12 to 24 hour period i would reduce it to maybe 800 and monitor.

Peace Out and much respect rkymtnman!

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See chart above.

Good morning, fellow growers. Another update.

Yesterday evening, before lights out at 7:00 p.m., I topped off the reservoir with RO water and adjusted my PH to 6.4 (knowing that it would drop overnight). PPMs were measured at 600 and EC at 1.2.

Soon after lights on at 7:00 a.m., I took my morning measurements: PH dropped to 6.1, PPMs increased slightly to 610, EC remained stable at 1.2, and my water level dropped overnight about a half-quart. I topped off the reservoir with nutrient-enriched tap water. The plant itself looks fine with no apparent deficiencies or nutrient-burn. She continues to gain in height each day.

So according to the chart: Water level falling, EC static, PH falling = Res change plus a change of EC. Lower EC if over 1.4, raise EC if lower than 1.0

So the way I understand the chart, I guess I need to do a res change but keeping the nutrients at their current level? Tomorrow (Sunday) is my normal reservoir change-out day, so I'll wait until then to do it. Tonight, I'll check the plant again prior to lights out tonight at 7:00 p.m. to see how the day went.

neckpod said:

I Believe your ppm can rise for a number of reasons including high temps, it all depends how fast it is going up and if the water level is dropping with the rise at a decent rate,
I try and have my ppm slowly rising and i mean slowly, a slow rise in ppm with nutrient levels going down shows they are getting what they need from the nutrients but a fast rise as you say is a big issue and needs addressing asap.
ppm going down means they need more and ppm not moving is desirable.

My ppm is currently going up from 930 to 1000 (tds) over a 2 to 3 day period and i have no issues at all no burn nothing, Now if this rise was happening over a 12 to 24 hour period i would reduce it to maybe 800 and monitor.

Peace Out and much respect rkymtnman!

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His vpd is like 12 which is around the 10 recommended so I dont think water loss is the cause, but your right. High heat summers I purposely run lower feeds to prevent this EC rise

@John1961

go back to page 1 if you don't mind and let give you a theory:

original conditions: static water, static EC, falling pH CO2 is possible cause. you said your furnace turning on not too long ago.

let me ask:

does that cabinet have fresh air being sucked/pumped in?
is it sealed and you run co2?
did you ever try moving your airpump outside the grow cabinet?

@rkymtnman -

The cabinet measures 2.4 x 2.4 x 5.0. I have a 120mm PC fan that pushes fresh air in at the bottom rear of the cabinet. At the top of the cabinet I have a squirrel-cage extraction fan rated at 53 cfm. Based on the total volume of the cabinet (~28 cubic feet), I figure the extraction fan is exchanging the air in the cabinet a bit less than twice a minute. I currently have the carbon filter removed so as not to restrict airflow in any way but I'll add it back once buds start forming and smell increases. The filter is a Phresh 4 x 12 unit rated at 200 cfm.

The cabinet is sealed so that the only air entry and exit points are the intake and extraction fans. I do not run any CO2.

I have not yet tried moving my air pump outside of the cabinet.

John1961 said:

@rkymtnman -

The cabinet measures 2.4 x 2.4 x 5.0. I have a 120mm PC fan that pushes fresh air in at the bottom rear of the cabinet. At the top of the cabinet I have a squirrel-cage extraction fan rated at 53 cfm. Based on the total volume of the cabinet (~28 cubic feet), I figure the extraction fan is exchanging the air in the cabinet a bit less than twice a minute. I currently have the carbon filter removed so as not to restrict airflow in any way but I'll add it back once buds start forming and smell increases. The filter is a Phresh 4 x 12 unit rated at 200 cfm.

The cabinet is sealed so that the only air entry and exit points are the intake and extraction fans. I do not run any CO2.

I have not yet tried moving my air pump outside of the cabinet.

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disregard theory. that's plenty of air movement. just a thought.

Jypsy Dog said:

Just something I had.

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Read the third line from the top. Then try moving the air pump for 24 hrs.

Good evening ladies and gents. Here are tonight's numbers at lights-off:

Air Temp: 69
Water Temp: 65.6
Humidity: 29
PH: Dropped to 5.7, added 4ml of PH-Up to reservoir to get PH to 6.2
PPM: 630 ppm prior to topping off with RO water; after top off: 620 ppm
EC: 1.3 prior to topping off with RO water; after top off: 1.2
Water level: Dropped another quart in the last 12 hours

Jypsy Dog said:

See chart above.

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I don't do charts, my girls tell me everything I need to know. Might of only been hydro for just over a year but been growing for 12 years now. Experience beats any chart.

neckpod said:

I don't do charts, my girls tell me everything I need to know. Might of only been hydro for just over a year but been growing for 12 years now. Experience beats any chart.

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Why respond to a comment obviously NOT MENT FOR YOU? You must be VERY proud of your growing skills. Thirsty much?

Good morning, folks. Here are this morning's numbers, soon after lights on:

• Air Temp: 72
• Water Temp: 67.8
• Humidity: 26
• PH: Dropped to 5.9
• PPM: Dropped to 610
• EC: Stable at 1.2
• Water level: Dropped a bit more than a pint overnight

Sunday is my normal reservoir change-out day, but since I just changed the reservoir this past Wednesday, I think I'll be safe enough to let it go until next weekend.

Well, I think this thread has run its course. In summary, I have something driving down PH each night. What that is cannot be determined. Switching to tap water helped limit those PH swings but I still have no choice but to use PH-Up each day to keep the reservoir PH within range. I guess whether I'm chasing the PH upwards or driving it downwards, as long as the PH stays and varies within the range of 5.5 to 6.5, I should be OK. At least I got my air and water temperatures in a better range thanks to the use of the "foot warmer" heating pad.

Thanks everyone who responded and offered help. I sincerely appreciate it.

Good luck John

Dont stress it. Its unrealistic to expect pH not to drift. Theres really no difference going up or down so long as you keep it as best in the range as possible.

The sooner you learn to stop babying your plants the better off you will be.