HELP! Hydro- pH drop

[YYCannabis]

Hydro
autos 14 wks old
18/6

ph was fine yesterday at 6.2 and water level was about 3” below basket. Today pH dropped to 3.8!!! and the girl must have drank 2 gallons of water almost emptying her pail.

I’m not sure if she’s telling me she want more nutes or less nutes. I’m guessing at 14 wks, 10th wk of flowering, that she is wanting less. She still has at least another week to go before flush.

I have this handy chart, but the one snafu is that it refers to measuring EC whereas I can only measure PPM. From looking at conversion tables, in America the conversion rate from ppm to ec is .5. But my ppm tester is totally Chinese, which means the rate could be .65 or even .7 depending on “what part of the world you live in”. Gunna do a full res change and lower the feed from the previous change 3 days ago.

Anyways...here’s the chart.

[Tersky]

EC is the measurement taken that is then converted to PPM based on scale used. It has nothing to do with region. A Chinese TDS meter uses the same scale as an american one. If you have a ppm meter instead of a tds meter then it could be a 500 or 700 scale, which is either EC x 500 or EC x 700 https://support.bluelab.com/hc/en-us...-do-they-mean- I have a tds meter which measures both ec and ppm (at 500 scale) but regardless the chart still works. If ppm goes up then ec goes up. Ppm goes down then ec goes down. Your plant is closing in on harvest. That happens to me the last couple weeks usually.

[Toker1]

She is drinking more water than nutes. Nutes are slightly more acidic so when water is consumed faster, PH drops.
You want to be in the 5.5-6.5 range. On a typical grow, you adjust down to 5.5 and 3-4 days later...you are at 6.5 and need to adjust back down again.
What have your water temps been like? Water temp fluctuations can cause PH fluctuations.

[Eliot Pryor]

I run dwc in 5 gal. buckets, 3 gals. water. When the plant goes to budding it drinks about 2 quarts of water a day. The ph drops. I add 1 gal. of water with a higher ph. I change the whole bucket every 7 to 14 days depending on how big the plant is and how I feel.(old I don't make excuses) Have a great grow !!

[starramus]

I don't do hydro, but that is exactly what I was going to suggest.

[starramus]

If you want to drop some dinero you can put it on auto pilot. https://www.amazon.com/Bluelab-Contr...xpY2s9dHJ1ZQ== (leave the driving to us!) https://youtu.be/YOokDxgr0pk

[YYCannabis]

Very interesting.

[YYCannabis]

I did a full bucket change 3 days ago and reduced nutes. First 2 days everything was was fine...water level dropping, PPM steady, pH staying stable.

From yesterday to today she’s done the same thing. As 3 days ago. Drank a ton of water, pH crashes again to under 4, and just a slight elevation in PPM (from 390 to 440).

Am I still too strong on the nutes? Since she pretty close to being done, I’m thinking she telling me she’s done. 🤣

Feedback is welcome.

[Obi-Wan]

Did she drink the bucket almost dry again? 390 to 440 isn’t that big of a shift in ppm if your water volume was reduced by 75% or more. I’d say try to top her of more often and that should level off your pH problems. If she’s still drinking, she’s not done.

[YYCannabis]

First 2 days was about .5 gallons of water. Last 24 hours was over a full gallon.
I did another full water change tonight. And lowered the nute level a wee bit. With the weekend almost here, I’ll be able to do some checks every few hours to keep closer track of what’s happening.

[YYCannabis]

She doing it again. This time in only 48 hours she crashed. I’m going to top her up with pH water to hold her over til morning. And see how tomorrow goes. She’s so close to being done that I think I will start flushing Wednesday.