PH drops overnight in flowering PLEASE HELP!!!

[teddysx3]

Hello gurus,

I have a serious problem with my PH dropping overnight by 1-2 points! My setup is like this: Hydro with bubblponics, lots of bubbles. The temperature of the water is between 62-66, keeping it a little cooler because I had root problem during veg with higher water temps. The temp inside the grow room during the dark period is 62-68 celcius, during the light period is 69-75 celcius. I'm feeding between 400-550 ppm on the 500ppm scale nutrients. GHE/TA trio, going half the size by the bottle. I'm not sure.anymore what the problem is. Is the water too cold? Is the nutes too much or too little and the plants drink too much water and PH drops? I change the reservior every week, but the ppm almost stays the same and only PH drops, so the plants are drinking only... I give them ph up every day to get them up to 6.0 - 6.5 and after 24h it drops do 5.0 even 4.5... The plants are showing signs more and more, I get it stable adjusting the ph every day, but they still are showing burnt tips, curling up tips and now the ends of the leafs are pointing up, heat stress? They are also starting from time to time show signes of other nute deficiencies because of the low PH... Can anybody help me out here? Thanks!!!

[DW2]

Howdy teddysx3, Are You sure of the temperature values that You posted above? 75° C is 167° F and 62° C is 145.7° F! If these temperatures are in Fahrenheit then they should be good, if in Celsius, then You are cooking the plants!
I have been growing in a Bubblephonics set up as well and IF the temperatures are in Fahrenheit then I would suspect that the nutrient levels are too low, causing the plants to take up all of the available nutrients in the water causing the pH to drop. The pH level does drop as the nutrients are absorbed by the plants and is not a cause for alarm, as long as they are within the range of 5.5 to 6.5.
In the past I almost killed of my plants by overreacting to the natural (but did know know at the time) pH shift and tried to keep it at the 'magic' number of 6.0. Now I let it fluctuate between 5.5 and 6.5 and only adjust it when feeding or topping off the reservoir at mid week.
I do not use a PPM meter, I feed at the rates suggested for the nutrient line (GH MaxiGrow and MaxiBloom) schedule and have had great results.
Good luck with Your grow.

[9fingerleafs]

Man I have some info for you. Remember I told you I was using maxigrow. Turns out I spend more money on ph up than buying ph buffered nutrients. And I found an excellent product at a very affordable price. I’m sure you’ve heard about jacks hydro. In my country it’s called “peters professional” but it’s there same product. It’s a full mix that only lacks calcium nitrate and in some versions magnesium sulfate. The one I got has mag and sulfur so I just add calcium nitrate. I got a 25 pound bag for 50 usd including shipping. Check it out.

[DW2]

Howdy 9fingerleafs, I have not heard of 'Jack's Hydro' before. I have been using the GH MaxiGrow and MaxiBloom for several years now but I have only used (on average) about 1/2 teaspoon of the dry GH pH-up each feeding, I am still working on the second bag (2.2 lbs.) of it that I bought a couple of years ago, so it is one of the lesser costs of the hydro to me. I have not seen the Jack's at any of the local outlets nor on line with the supplier that I have been using.
Thanks for the information, if I run across it, I may try it out.

[9fingerleafs]

I’m not a hydro grower teddy so I’d rather wait before I give you bad advice. In my opinion Gh has a tendency to be too acidic in general

[teddysx3]

Hello DW2..Sorry about the degrees...Yes they are in F, I had written them in C first, but thought It would be more easier for you guys in F.

I also suspect the nutes are too low, and this could be the problem, But I'm scared to give them 700-800 ppm on the 500ppm scale, but I will try the next time i change the reservoir.

The problem is the nutrients when I change the water, for 1-2 days are absorbed normally, and after that they stay the same for days, and I have to adjust PH every night to 6-6.5 so I have enough room to drop to 5 the next day...Also sometime the nutrients rise in PPM which is really strange, due to the very low ph...

[teddysx3]

Howdy teddysx3, Are You sure of the temperature values that You posted above? 75° C is 167° F and 62° C is 145.7° F! If these temperatures are in Fahrenheit then they should be good, if in Celsius, then You are cooking the plants!
I have been growing in a Bubblephonics set up as well and IF the temperatures are in Fahrenheit then I would suspect that the nutrient levels are too low, causing the plants to take up all of the available nutrients in the water causing the pH to drop. The pH level does drop as the nutrients are absorbed by the plants and is not a cause for alarm, as long as they are within the range of 5.5 to 6.5.
In the past I almost killed of my plants by overreacting to the natural (but did know know at the time) pH shift and tried to keep it at the 'magic' number of 6.0. Now I let it fluctuate between 5.5 and 6.5 and only adjust it when feeding or topping off the reservoir at mid week.
I do not use a PPM meter, I feed at the rates suggested for the nutrient line (GH MaxiGrow and MaxiBloom) schedule and have had great results.
Good luck with Your grow.

Sorry, didn't quote you.