PH drops significantly only two weeks into veg

[Rexer]

Hmm well I'm at a loss....do you have a valve (carb) on your air pump? Maybe try turning the air down.

I'm at a loss, so let's get some extra eyes and thoughts if they don't mind?
@Tokin Roll @West Hippie @Dusty Kiefers

These three guys know the ins & outs of DWC better then I, and I believe all have use General Hydroponics nutes.

 

[sneekymofo]

I wouldn’t be shocked if you found a chunk of something unexpected when you break it down. I hope it’s something simple like a mass that is just hung somewhere acidifying the mix. Very much good luck - fingers crossed that it is something simple…..

 

[West Hippie]

Thanks for the tag @Rexer
Does the ph stop at 5.6 or does it keep dropping. Mine started dropping like that with 5 grams a gallon of MC nutrients, but kept hitting 4.6-4.8 in the DWC .

 

[RaggedyMan]

Hmm well I'm at a loss....do you have a valve (carb) on your air pump? Maybe try turning the air down.

I'm at a loss, so let's get some extra eyes and thoughts if they don't mind?
@Tokin Roll @West Hippie @Dusty Kiefers

These three guys know the ins & outs of DWC better then I, and I believe all have use General Hydroponics nutes.

You said something in an earlier response about how I didn’t mention a new air pump. Could this old one be failing in some way and injecting acidic “stuff” (sounds crazy to me). I have a new one on the shelf I think I’ll swap them out.
I’m going to cut the air down in the 2 tanks that have no plants
I was hoping to find a dead mouse or something dammit in one of those totes. The system sat unused for 2 months after cleaning from last grow. I covered everything up but those critters can be sneaky

 

[Rexer]

You said something in an earlier response about how I didn’t mention a new air pump. Could this old one be failing in some way and injecting acidic “stuff” (sounds crazy to me). I have a new one on the shelf I think I’ll swap them out.
I’m going to cut the air down in the 2 tanks that have no plants
I was hoping to find a dead mouse or something dammit in one of those totes. The system sat unused for 2 months after cleaning from last grow. I covered everything up but those critters can be sneaky

The air pump is a long shot, I wouldn't buy a new one, just thought to ask.

Well, there is one other option, and that's to use some H202 (food grade) at 3%. It'll kill any beneficial microbes, but also any pathogens that could be causing it. You can always re-add beneficial bacteria after 3 or 4 days (from adding the h202). I'd see what the others think before making any other changes.

How low does the ph drop? What's the lowest it's dropped to?

 

[RaggedyMan]

Thanks for the tag @Rexer
Does the ph stop at 5.6 or does it keep dropping. Mine started dropping like that with 5 grams a gallon of MC nutrients, but kept hitting 4.6-4.8 in the DWC .

I don’t know if it stops there or if it would keep going. I check it first thing in the morning and start pumping ph up in

 

[RaggedyMan]

I’ve been looking at the blue lab ph controllers. I always think about them when I’m fighting the acid of late flowering but now might be a good time to buy. I’m going to be gone 2 nights this weekend, 5 next weekend, 7 in mid September and again in October. I would rather cure than simply treat the symptoms but this may have to do while I’m away

 

[RaggedyMan]

Any recommendations on a controller? I have the blue lab monitor and like it. I don’t mind spending the money but if there is something comparable and cheaper…….

 

[Rexer]

I’ve been looking at the blue lab ph controllers. I always think about them when I’m fighting the acid of late flowering but now might be a good time to buy. I’m going to be gone 2 nights this weekend, 5 next weekend, 7 in mid September and again in October. I would rather cure than simply treat the symptoms but this may have to do while I’m away

I've been wanting one of those badly! If it's an option, go for it! Like you said, it's not treating the problem, but for future grows, you'll thank yourself (from what I've heard).

The only two brands I know of are blue lab and Milwaukee Instruments, and Blue lab is supposed to be top shelf equipment.

 

[RaggedyMan]

Well now, isn’t this interesting!!!
Ph was at 6.4 this morning. Exactly where it was yesterday when I changed out my air pump for the new one and reduced the airflow to one tank only.

I did not empty/change the reservoir solution to look for anything that may have been in my totes that shouldn’t be but rather just took the lids off.

Could it be the new air pump, the reduced airflow or that my rdwc system knew I spent nearly $500 ordering a piece of equipment?
Today I will open open the airflow to it’s normal settings and see what tomorrow brings. Oh, and @Rexer , the ppm is now at 420 (50 of that is likely ph up from yesterday’s adjustments) and plants seem to like it ok

 

[Rexer]

Well now, isn’t this interesting!!!
Ph was at 6.4 this morning. Exactly where it was yesterday when I changed out my air pump for the new one and reduced the airflow to one tank only.

I did not empty/change the reservoir solution to look for anything that may have been in my totes that shouldn’t be but rather just took the lids off.

Could it be the new air pump, the reduced airflow or that my rdwc system knew I spent nearly $500 ordering a piece of equipment?
Today I will open open the airflow to it’s normal settings and see what tomorrow brings. Oh, and @Rexer , the ppm is now at 420 (50 of that is likely ph up from yesterday’s adjustments) and plants seem to like it ok

Now that is some great news!

Now was it the pump, or the bump? The fact their not leaching back is a great sign. Keep an eye on your water level, make sure they're drinking again.

Im so happy that the ph drop is under control! And if it was the air pump, then my sincerest apologizes for having said it was not likely the air pump.

 

[RaggedyMan]

I’ve decided it’s too close to my weekend absence to be farting around with testing to see what specifically caused this and since I’m going to be gone 5 nights the following week I’ll likely just leave well enough alone for the next couple weeks.
I do want to follow up though if for no other reason than to confirm the cause and post it here so future hydro growers will have something to consider

 

[sneekymofo]

Definitely keep us posted Raggedy! It can happen to any of us!

 

[RaggedyMan]

Definitely keep us posted Raggedy! It can happen to any of us!

Now that you mention it……
I went out of town and had a friend check on everything for me. The ph was holding at 6.2 but misreading my note he added half the ph solution I had set aside for him which brought it to 6.7. A little higher than I wanted so when I got home the next day I changed out half my rez to bring the ph down rather than add ph down. Ever since then it’s been wanting to drop.
I installed the bluelab controller I ordered and it’s keeping the rez where I set it at 6.0 but there’s still something obviously going on. I feel like pumping ph up in on an almost continuous basis (controller is set at 5ml every hour as needed) can’t be a good thing but plants are looking good at just over 3 weeks old. I’ve topped and lst’d all I’m going to I think so now just to let them grow.
I’m leaving again tomorrow for 4 nights so it’ll have to do until I get back.

 

[RaggedyMan]

I was researching the general hydroponics ph up and see that it’s a potassium based solution. Is adding this regularly screwing up my nutrient profile? As I said before, the plants look damn good but am I going to have problems later maybe?

 

[ColonelBlake]

Hello Raggedy.

I have 2 years of RDWC under my belt. I'm not an expert by any stretch, but I've seen quite a few things in those 2 years. Here's my hip shot advice - some of which has been noted already.

* Be very thorough about eliminating ALL light leaks. This includes white pvc. If in doubt, stick a flashlight on one side and see if you can see it on the other. If you can, then it's a light leak. I put black pipe insulation on all my pvc - with the dual benefit of it a) blocking light, and b) insulating the water ( keeping it cold ). **I see 3 holes in your last pic that look like light leaks to me.**

* I don't care what anyone says. It's hard to overdo aeration. I run a 1/2 hp regenerative blower on my 36 site system w/ 2 large air stones in each 5 gallon bucket. This would be an overkill for you obviously. You water should bubble vigorously imho.

* Water quality is imperative. I use an RO system w/ a UV sterilizer at the end. Some can use tap water without issue. I cannot. You could also bleach your water 24-48 hours before you use it ( 2 ppm or so ) to kill all micro organisms.

* Use beneficial bacteria OR go the sterile route. I've tried both. The latter works best for me. I use small amounts of chlorine dioxide when necessary. I use and ORP meter to determine when. I keep a range between 400-450mv usually. I've also heard really good things about Hydroguard, Photosynthesis Plus, and many other beneficials. I just never had very good luck with them.

* Keep your area very clean. After each grow, sterilize your grow if possible. I run 50-100ppm mixture of chlorine dioxide through my system for an hour or so. It's great at eliminating biofilm. The product that I use is 'Oxine' w/ added citric acid. You'd have to read up on this if your interested. But basically you add 10% citric acid to Oxine and let it sit for 5 minutes to activate.

* Your initial EC looked low to me. I see you've upped it to 1.0EC though. That seems more in line. I keep mine between 1.4 - 1.6. But it really varies on the strain, your setup, plant size, the environment, etc.

* Keep your nutrients line simple and synthetic. Never add anything organic - otherwise you will get a full on bacterial explosion. I use Jacks 321, Calimagic, and ProSI. I'm not totally sold on the silica yet. I use calmag because I'm using RO, and the plants seem to require it. Jacks is a very cheap and effective fert. They've been around for many decades and know wtf they are doing.

* Water temperature is a big f-ing deal. Keep it 68 or less. 65 being the sweet spot for me. Looks like you are on top of this already tho!

* Res changes are a must. I do a res change weekly. Some go longer - like every 2-4 weeks. Jacks is so cheap that it's really a no-brainer for me to change it weekly so all the nutrient levels are to the perfect. My res is ~100 gallons.

Hope this helps.

 

[West Hippie]

@RaggedyMan I’d set the ph to 5.8 so you’d be in the middle of cal/mag absorption.

 

[Delps8]

I was researching the general hydroponics ph up and see that it’s a potassium based solution. Is adding this regularly screwing up my nutrient profile? As I said before, the plants look damn good but am I going to have problems later maybe?

I would be surprised if that was the case.

I say that for two reasons - the amount of Up you're adding is very small, in the order of a few CC's, and you're adding that to a 40 gallon res (lots of CC's… 151,416 CC's, in fact). That's a tiny percentage of the volume of the res.

The other issue is that, if there was a concern about throwing nutrient balance off, I would expect that GH would design their product to minimize the impact or they would add a warning to the bottle. After all, the last thing they want is to have growers "add a little Up" to raise the pH so was to allow proper nutrient uptake and then muck things up with a chemical that exacerbates the problem.

For my money, granted that I have zero actual evidence, I'd posit that the impact is "Measurable but insignificant."

 

[Delps8]

The reason I've poked my nose into this - I've only done two grows, one in 2017 which ended up flowering but not being harvested, and a grow earlier this year (4 GG autos). The 2017 grow was hand to hand combat - me vs pH. Overall, I think it was a draw but I chased pH up and down. When I unarchived my grow equipment this year, I decided to do it right and that's when I found the WonderChart (the chart that Rexer provided) and "Son of WonderChart" (attached).

The footnotes for the WonderChart are here:
"
"Note 1.
When pumping air into a nutrient solution in order to add Dissolved Oxygen, not only oxygen is present, CO2 is also pumped in. If you live near a busy road, this may be higher than normal, so you may get a dropping ph quite often. I have noticed most of the growers who suffer from a falling ph in DWC tend to live in large cities. This may not be a link but it could be.
When CO2 is added to water, it makes it more acidic. This is the precise process which causes acid rain, pollution from power stations etc pouring CO2 into the air, this mixes with the water vapor in clouds causing acid rain.

Note 2.
Most people assume that with a rising EC, it is the plants way of saying, I don’t want more food, here, have some back.
What is actually happening is this.
Plants roots take in water/nutrients through a process called Osmosis. Think of the roots as having their own "internal EC".
The osmosis process will always try to balance out the EC's, taking from the higher side of the barrier and giving to the lower part.
So if the EC of the nutrient solution is higher than the "internal EC", then food & water will flow from the solution to the roots, this is the normal process.
If however, the EC of the solution is lower than the "internal EC", then the balancing will work the other way and nutrition will be leeched from the roots to the solution.
A res change or increase in EC should resolve depending on the other factors such as ph and water levels.

Note 3.
Nutrients flow around a well hydrated plant much more effectively and faster than one which isn’t as well hydrated.
How can growers use this?
By feeding at lower levels, the plant needs to take on more water in order to get the nutrition it requires.
So by feeding at moderate levels, this forces the plant to drink more.
By drinking more, it is better hydrated, because it is better hydrated, it needs more food, making it eat more.
So feed at moderate levels rather than overly aggressive levels.
The method of pushing the EC until you see signs of nute burn is damaging to the plants and although many growers use this method, I am not a fan though your plants are not mine!

If you disagree with stuff in this post, please PM me. I do not want this thread to end up as a big debate or argument. I am hoping people take it as an honest attempt to help those suffering issues in DWC. The info in this post is my opinion. Before taking any corrective action based on this post, please double check."

I have edited the text only for readability.

 

[West Hippie]

I didn’t see no poking , I see useful information and I thank you for sharing. What you did is what 420 Magazine is about sharing . I like the chart also , I also use the hydro bible that @Rexer put in post 7 of this thread . What do you think of the hydro bible?