Drop in pH..but good growth...????

Hi all. I'm about 3 weeks into vegging and my girls look great. Lush and healthy. I've been experiencing slight drops in pH like from 6.0 to 5.7 or 5.7 to 5.5 during the light cycle. I'm not sure what it means or if it's fine or what.

TDS at the last rez change (5 days ago) was about 1700 with all nutes and supplements combined. The plants took very well to it. TDS today is 1370 so the plants are using up the nutes. Usually when plants use nutes the pH tends to increase a bit, not decrease, or so I have read.

I have a feeling the plants are almost "self-adjusting" themselves to their desired pH level. I am going to ask the seed breeder what he thinks.

What do you guys think? Is it cause for concern?

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Originally Posted by Passage to Indica

Hi all. I'm about 3 weeks into vegging and my girls look great. Lush and healthy. I've been experiencing slight drops in pH like from 6.0 to 5.7 or 5.7 to 5.5 during the light cycle. I'm not sure what it means or if it's fine or what.

TDS at the last rez change (5 days ago) was about 1700 with all nutes and supplements combined. The plants took very well to it. TDS today is 1370 so the plants are using up the nutes. Usually when plants use nutes the pH tends to increase a bit, not decrease, or so I have read.

I have a feeling the plants are almost "self-adjusting" themselves to their desired pH level. I am going to ask the seed breeder what he thinks.

What do you guys think? Is it cause for concern?

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Two things. First, 5.5 and 5.8 are all within the desired hydro pH level, everyone has their own reasons and Im sure some plants like different things. That being said, pH that is constantly moving up and down will not treat the plants as best as having something more solid. Can you use a larger reservoir? Can you find water that starts out with a better pH? What are you pHing the water with? Are you pHing down or up? The down turned leaves looks to me like too high or too low of pH or high rez temps. 6.0 pH is too high. I let mine float around 5.7-5.8, but then again its easier for me with a larger rez.

I've had an issue with having to PH up all of the time. I use RO water and was using GH's PH Up a few times per day. I finally tried a tiny bit of baking soda disolved in water and used that, and my PH has been far more stable since using it.
Results could vary obviously, and it's not generally recommended over the store bought ph up. But the baking soda also helps buffer the ph, so it's worth trying anyway to see if you can go longer between adjustments.

Mr E, I switched my plants over to bloom about 2 weeks ago and finally noticed (several grows in) that the ph level in blooming nutes lean very strongly downward. I had been having the same issue you had recently...was using baking soda to keep it up but it would drop overnight which it NEVER did with the grow nutes. Guess I have been paying more attention since my molasses party. I'm now almost 3 weeks in 12/12 and am noticing the plants are now big enough to start shift the ph back upward. I'm convinced it's something in the difference between the grow and bloom nutes.

Hm I dont know. I'd been on grow nutes when it first happened to me. But could be though. PH can be a little hard to nail down I guess, so many variables, but it's important. This has been my first hydro grow, so steep learning curve for sure.

As it is now, I know I might need to up it 1 10th each morning, at the very most. And that seems pretty good so I'm not fooling with methods until next time.

not much to report today although last night the pH dropped again from 5.5 to 5.3. I thought It would level out around 5.5 but it continued to drop so I added some pH up to bring it back up to 5.9. Rez change tommorow......switching to 12/12. I think I will use a slightly weaker nute nute mix to see what the pH does. Target TDS with supplements....1500

This is a really good article on water chemistry that talks about PH buffers and much more: International Cannagraphic Magazine Forums - BigTokes ~ Basic Water Chemistry!!

I have noticed PH tends to start to drop as the rez hits about day 7 or 8 and the plant has spit some waste back into it. Im not sure if i'm right though on my reasoning. Anyone?

I don't know either, I sure would like to know. Maybe Zandor can chime in on this common question.

You know I honestly never have had the problem until this grow and it definitely happened as soon as I switched to bloom nutes.....I kept my plants on grow for the first week of 12/12 at Zandor's and lw's suggestion so I know it wasn't the lighting......definitely the nutes and since the plants have grown like beasts I am starting to see the shift back to the ph rising slowly. I don't think it has anything to do with how old the solution is because it seems to happen even with a fresh res change. I agree with Mr E that small amounts of baking soda seem work better keeping the ph up than the normal ph up seems to.

I wonder if shaking the bottle of pH up (or down) would make a difference? Or perhaps age of the bottle and it's contents has a part in it too. Like I said though, I used to only have increases in pH, not decreases.

I would imagine age of the product can affect ph down, since the acid percentage is so low it breaks down over time. I used to have this problem with acid for my pool after winter. But it would make it weaker, needing more to bring it down.

wonder if pH up does the same

Changed rez, hit target ppm at 1550. I trimmed some lower fan leaves, starting to get a bit congested down there.

switching to 12/12. sit down, strap in, and hold on!!!!!



28 days from seed, 24 days of 18/6. So easy!!!!!

Hmm that doesn't sound right, from what I know a healthy nute mix will go up over time...the only time you should need PH up is if you over do the PH down. I bet Zandor or LW knows though...also could confirm what I stated.

Zandor has posted recently that undernuting could cause PH drop too. But he's at around 1500 so that seems unlikely provided everything is calibrated.

I sure couldnt figure out why mine just drops, but it does. I havent used any PH Down since I changed to RO water. With my plain tap water, I had to down it like crazy though.

I'm sorry you guys but I am stuck on those bloom nutes. When I mixed up the grow nutes the ph naturally went to 5.7...never had to adjust it before I put new stuff in. With the pro-bloom when I mix the ph stands at 4.6 until I adjust it up with baking soda before I add it to the rez. I am willing to swear to this in court, lol:D I have found this grow that the ph will drop a little the first day then start to go up slowly. I also could not keep my ph down with well water which is why I switched to RO.

7 days of 12/12 after 28 days of 18/6 32 days from seed

I have done a lot of trimming to keep things under control such as lower fan leaves, lower side branches, and I topped the tallest plant to keep her low as the others catch up. I grow from seed so it's not unusual for me to get two or three different size or shape plants. I'm a little surprised that I have three different size/shape plants with this strain however, as Easy Bud from Femaleseeds.nl is said to be very stabile. All I really need from the three plants is 5 or six of each plants best kolas to rise to the top and I will have a canopy full of donkey dicks. THe rest is all gravy.

One thing about RO water, it has like ZERO buffering, so it can shoot all over the place. Try throwing in say 1/2 gal tap water for every 5 gal of RO water. That shouldn't hurt anything, but tap water is usually buffered pretty well. Just let it sit overnight to get out the chlorine, or boil it first.