HYDRO Rdwc dropping ph and 3 plants under the weather- small twisted ugly- roots look great

[HatRack]

Hey guys looking for a little help system has been steadily drooping in ph also ppms def not as much. Everything iv read and what current culture says is ph should be rising and i should only ever have to add little amounts of down. Have tried increasing ppms to almost where they say for there systems ,this is a diy with more air than they run-150lpm to a 45 gallon system using bubble tubes which i beleive put out less air than stones,anyways thats why iv stayed a little under on ppms than they recommend but above what they recommend for systems with my air amounts- they have two scheduals to follow. Also have 3 out of the twelve that are stunted and growing twisted compared to the rest but not sure if they have anything to do with my ph issue or there just duds comapred to the others. I did have a few issues in veg which was my fault, adding ph up directly to rez, opps, and prob to often also. Any help appreciated will upload a few pics of stunted ones tonight when lights on, Thanks in advance

[DW2]

Howdy HatRack, The pH of the system can cause more problems than one might expect since the plants take up different nutrients at different pH levels causing systems that can appear to be nutrient deficiencies. Some plastic containers can, adversely affect the stability of the pH of the water nutrient mix. I had trouble keeping the pH steady for the first couple of grows. I constantly 'chased' the pH up and down, nearly killing my plants in the process. I decided to stop the chase and just start off with the nutrient mix in the range of 5.5 to 6.5 and letting it fluctuate. The pH should rise (and the PPM lowers) as the plants take up the nutrients, The amount of air put in by the air stones can change the pH of the solution as well, but, I would not recommend reducing the air in the water because the O2 is very important to the roots.
I do not know for certain why the pH is affected by the container, most likely, chemicals, from the manufacturing process, leeching out over time. If I was going to start a new reservoir, I think that it would be wise to soak the reservoir filled with pH 7.0 water to see how it will affect the pH after a few days. A solution (either acidic or basic) could then be added to neutralize the leeching chemical. This is just speculation on my part as I have not tried it on a new reservoir, but the pH problem did clear up with repeated use of the reservoirs that I have now.
Good luck with Your grow.

[HatRack]

So when you say repeated use like are we talking several grows or what. And i wish i could let it drift but it seems to just keep dropping. Ill start at 6.1 or 6.2 and be down to 5.5 in a day and that with the higher top off rez and them drinking gallons a day

[DW2]

HatRack, It took until the third grow before I started to get things going right. A combination of gaining experience and 'washing out' what ever was in the plastic. What I started doing was first, not adjusting the pH directly in the reservoir, I S.W.A.G.ed (scientific wild assed guess) for the pH of the top off water, i.e. if the reservoir checked at 6.5 pH, I would adjust the top off water to around 5.0 (mainly depends on the amount to be added for the top off), or if the pH in the reservoir was at 5.5, I would adjust the top off water to around 6.0 to 6.5.
The most important thing now would be to get the system to stabilize. You might try a good flush using a pre harvest flush (I use GH FloraKleen) to help to prevent the plants from going into nutrient lock-out.
For what it's worth, My first DWC set up was a Bubbleponics set up, a black plastic (generic no name) 10 gallon tote and is the one that gave Me the most problems. The second set up I made using a 10 gallon Sterilite tote. silver grey in color (do not use one that lets ANY light thru) and it gave me fewer problems with the pH, but I did wash it out before using it. A per use soak of around 24 to 48 hours, using a flushing agent, might avoid future problems.

[Toker1]

Yeah, new plastic has a period of PH flux. It will eventually stablize if all goes well enough. What you need are PH buffers, which are found in some hydro nutes (but not all of them). If you have isolated PH swings to the plant itself...When PH falls, that tells us they are drinking more water than they are nutrients. This tends to happen with excessively high temperatures.
What is your temp like by the canopy ?
what is the water temp like inside the reservoir?

[HatRack]

Hey not sure how the forum works if i need to comment for you to get notified but i replied to your questions. So are you implying that my solution is to strong when ya say there drinking more water than nutes. I have been on the low side the whole time i believe and most shit i read tells me if ph dropping ec needs to be raised?

[Toker1]

No... I meant there is something going on (possibly with heat) that’s causing more water to be absorbed than the nutrients. So the concentration of nutes increases with each gulp of water. The plant should be absorbing water and nutes some what equally. Causing PH to raise instead of drop. Btw, falling PH is also will increase your ec because the nutrients in the solution become more concentrated.

[HatRack]

Hey guys thanks for the replies .Temps have been between 68night and 75 day humidity between 40 night and 65 day water temp steady 68 since I got chiller which was about week two of veg. Plants are on week two flower right now. The whole new container thing makes sense. I just built this setup and fda food safe square buckets for everything except the rez and top up rez. There are drinkin alot of water I also should mention and also have some twisted growth and some of the top leaves have raised serrated edges. I'm lost as I feel like I have most variables dialed right in besides the ph ing and keeping it stable. Seems like it will just drop off forever and quick like with in a day from above 6 to under 5.5. ppms will also drop say 30 or so ppm. I also keep a top up rez with around 6 ph or higher and 100 ppm higher that auto fills the system.

[HatRack]

Just realized something else that could prob dispell the whole leaching buckets theory and push me more towards incorrect ec after looking back threw pics and notes... I had a rising ph in the beginning of veg when plants were not drinking much if any. What does everyone do when ph is dropping raise ppm or lower???