Ph problems in Deep Water Culture

[Bdbjmb]

So my first handful of dwc runs went well. A lot of tinkering & dialing in of course but overall, super productive. This time around my ph is consistently dropping and the only thing I'm really doing different is incorporating co2(via 2 exhale grow bags) in my 8×4 tent. I moved my air pump outside of the tent to prevent co2 being pumped into the reservoir. Still need to do a res change after moving the pump. Hopefully that helps. The thing is my plant is only a couple weeks old so I have just started seeing roots below the net pot. Any help with stabilizing my ph would be greatly appreciated!

 

[JadedMarxist]

Where do you vet your water from? More importantly tho where did you get your meter from? How low compared to yourstarting point does it go? What nutrients and what lvls ppm /ec?

 

[JadedMarxist]

Last question why CO2 bags? How much light are you giving them?

 

[Bdbjmb]

Trying co2 just because I never have before and I'm always trying to improve my grows. As far as everything else goes, I'm running an HLG650r
Get my water via my r/o filter
I have the blue lab guardian & blue lab combo meter(calibrated regularly)
Mills nutrients (which I'm not thrilled with)
200ppms(500ppm bracket)
Starting ph 6.2 overnight drops to 5.1
Thanks for the reply dude!

 

[JadedMarxist]

Seems like you got the basics down Pat.

Usually if mY ph dips it's a sign of root problems but you say your roots are not in the water yet.

How does your buckets smell like roots or getting musty? I found I can usually smell the start of root problems before my plant shows any symptoms.

How are the plants looking? If they are healthy will have wait and see.

Also usually I adjust my rain water to 5.5 let it slowly go up.

You may need to buffer the water as you took out any it previously had with the ro Filter, @Aquaman he can explain it with actual science talk. Lol

Also an idea adjust yourwaterph before adding ferts then again after.

Last one is your rez light proofed? Light on the water grows bad bacteria which cause root rot

 

[Bdbjmb]

Thanks alot for helping out dude. My rez is light proofed. We just bought a house so dialing in a new grow can be tough ya know. My old setup never gave me this problem, so that's what keeps leading me back to the co2. I hate to do away with it because I know how beneficial it can be, but if that's what causing this constant ph drop I guess I have no choice. Did a res change last night, washed everything, nothing smelled bad.
Starting ph-6.0
Wake up this am and sure enough, ph has dropped to 5.5.
Might try to take the co2 out for a day or two and see if it stops.
I also ordered Dutch master nutrients, because I'm just going to do anything to get this right. As I said before I'm not really loving the mills nutrient line. Going to keep fighting the good fight! Thanks again dude.

 

[Mazeblue1]

I use this as a reference and it helps alot

 

[Bdbjmb]

That's an awesome chart! Really appreciate that. It totally confirms my fears... So I wonder if it's just inevitable, in a 8×4 tent that co2 will find its way into my res.(even with my air pump being relocated outside the tent. Has anyone else tried running co2 in a small space while growing hydroponically? Again, thanks so much for the feedback. The grow community is so awesome!

 

[Aqua Man]

What nutrients are you using?

whats source water are you using?

200ppm is to low.

There are many reasons why ph will drop. Not all of them are bad.

If you ask me its likely an issue with alkalinity.

 

[Bdbjmb]

I have an r/o filter, my water starts at 0ppms-8.0-8.5ph
Currently running mills nutrients with botanicare cal-mag, hydrogaurd, and silica blast
Did a res change last night and increased ppms to 450 and ph set at 6.0. At this point today it has dropped to 5.0.
You think I should remove the co2 for a day or so to see if that's what's causing the ph drop? Do you think an 8×4 tent is too small a space to run co2 while growing dwc?

 

[Aqua Man]

I have an r/o filter, my water starts at 0ppms-8.0-8.5ph
Currently running mills nutrients with botanicare cal-mag, hydrogaurd, and silica blast
Did a res change last night and increased ppms to 450 and ph set at 6.0. At this point today it has dropped to 5.0.
You think I should remove the co2 for a day or so to see if that's what's causing the ph drop? Do you think an 8×4 tent is too small a space to run co2 while growing dwc?

Yup thats likely the issue... alkalinity. What type of silica is silica blast?

Have a read here.

Marijuana pH Levels for Growing Weed: A Basic Explanation

OK I'm going to do my best to explain PH since its something that is for the most part greatly misunderstood and can be confusing to new growers and even experienced growers alike. This will explain why we need both ppm and PH meters to give us informed information about PH This will be a...

www.thcfarmer.com

 

[Bdbjmb]

Awesome info dude! Silica blast is derived from potassium silicate. Can't thank u enough for helping out.

 

[Aqua Man]

Co2 is fine and its extremely hard to dissolve in water. I built my own co2 reactor to dissolve co2 in water and if you try to do this at atmospheric pressure in well aerated water even if the co2 is high like 1500ppm in the air you are going to have next to no impact on ph. Its an overblown bioscience that seem to have been regurgitated for a long time.

 

[Aqua Man]

Awesome info dude! Silica blast is derived from potassium silicate. Can't thank u enough for helping out.

So make sure you add that first... then allow 30 min to be safe before adding anything else. Use it at FULL dose. After 30 min ph down to 6.5 before adding your nutrients.

Then add the part containing micros. The add the other part and finally ph at the end to desired.

Check ph an hour or 2 later and adjust if needed.

Should solve your issue.

 

[Bdbjmb]

I'm on it! Thanks again, I'll post later and hopefully that'll be it. Happy growing

 

[AnselAdams]

Awesome info dude! Silica blast is derived from potassium silicate. Can't thank u enough for helping out.

Good Evening;

I have been dealing with the same problem lately and managed to get my PH stabilized.

First question i have for you is critical to maintaining your PH where you want it. What is the alkalinity of your water?
If that is not in the range of 40-60 ppm you are going to have problems. There are a number of test kits on the market that will give you a reasonably accurate reading. Without your alkalinity being right you are just spinning your wheels (and money on PHup/PHdown) trying to fight a battle for which you are not properly equipped.

Happy Growing!!

Additional Info you may find helpful; the entire article is very well written and informative: original url => https://manicbotanix.com/maximum-yield-hydroponic-gardening

 

[Bdbjmb]

So I guess I need to buy an alkalinity meter...
I added my silica blast first, and let it sit for 30mins just like Aquaman recommend.
Then adjusted ph to 6.5 before adding nutes.
Starting ph last night 6.0
20hrs later ph-5.4
So doing that certainly delayed or slowed down the ph drop, but it is still dropping! Unbelievable! It's just my luck to have such a problem. It seemed to be stable for a few hours but ultimately dropped over night. I really wanted to post that everything was fixed
So my next idea is to start with a blend of r/o water & tap water. Diluting tap until its 75ppms . Hopefully this, plus adding alkalinity via silica blast will help my res water's ph stay stable.
I'm totally open to other suggestions, in fact I'm hoping to get some! Happy growing everybody.

 

[AnselAdams]

So I guess I need to buy an alkalinity meter...
I added my silica blast first, and let it sit for 30mins just like Aquaman recommend.
Then adjusted ph to 6.5 before adding nutes.
Starting ph last night 6.0
20hrs later ph-5.4
So doing that certainly delayed or slowed down the ph drop, but it is still dropping! Unbelievable! It's just my luck to have such a problem. It seemed to be stable for a few hours but ultimately dropped over night. I really wanted to post that everything was fixed
So my next idea is to start with a blend of r/o water & tap water. Diluting tap until its 75ppms . Hopefully this, plus adding alkalinity via silica blast will help my res water's ph stay stable.
I'm totally open to other suggestions, in fact I'm hoping to get some! Happy growing everybody.

To stabilize your RO water try using regular old baking soda as described in the article. That will provide you with a good solid starting point. Tap water is going to put your starting ppm's too high as you add in your other nutes (even when diluted there may still be a lot of undesirables in the tap water). I added 9 grams of arm and hammer to my 40 gallon rez.

Happy Growing.

 

[TheBioMaster]

House & Garden makes a ph stabilizer made for RO water.....a liter will last you a lifetime!

You need to be using a enzyme product, and something to break up salts like Drip Clean or similar. You also need a good rinsing agent like Flawless Finish from Advanced.

All these little things add up to a stable running system.

Another option is to get rid of organic inputs......after time (1 grow cycle) bacteria blooms will cause the ph drop.

The organics build up inside your PVC pipes and hoses in very hard to reach places. Running sterile is about the only way to keep it in check, or use a nutrient with no organic compounds/components.

I've ran with organics for years in RDWC systems......it can be done. You have to be on point with air, water temp, circulation, water changes, proper water levels, and you have to do what I call a surgical cleaning after each grow cycle. This means taking apart the pipes, everything.

Its for sure not CO2 as this has been tested and you are not reaching nowhere near the levels required to affect ph levels with exhale bags. You could run 20 of those bags in your tent and not worry about it affecting ph.

 

[Bdbjmb]

Excellent info as always. I'm definitely going to look into that ph stabilizer, and baking soda.
And yea I don't run any organics in my indoor grow. The weirdest part of it is that I ran dwc systems in my apartment for 5yrs with great results before buying my new house. I never had this problem. This is my first run in the new house/new setup. The only new thing I've incorporated is co2. That's why I kept going back to that. But I'm on to getting my source water right. totally appreciate all of ur help dialing this puppy in!