Ph Drift

[MrMagic]

Im just wondering how much Ph drift people are getting. My plants are showing super bad signs of high Ph issues since the beginning of the new year. Unfortunately over the xmas holidays my plants got a little neglected due to the busyness and a few health issues. Purple stems and lime green leaves and signs of deficiencies, I lowered the Ph of my feed water to 6 down from 6.5 to 7, I started to add cal mag for the deficiencies, bumped up the nitrogen a bit. (i typically don't need to use full strength) I started watching my Ph closely and on water days my soil samples would show a Ph of approx. 6.3-6.5 and a quickie check with my probe showed roughly the same. 3days later when its time to water again my Ph would spike to 8. Again tested both with soil samples and a quick probe check. Yeah Yeah Yeah I know probes aren't accurate. I doesn't need to be accurate, in this case I just needs to be close enough to show a trend, and I back it up with soil sampling for double measure. I Ph my feedwater again down to 6 and same thing, starts out good then 3 or 4 days later back up to 8. When I feed my plants green up and the purple reseeds a bit from the leaf veins and stems, and by the time its time water again the purple comes back, leaves start to yellow and show deficiencies. So Im sure they are showing me high Ph and I trust my readings from what the plants are showing. What really makes it weird is that the soil I use is a little on the hot side at the beginning of a grow. I know Ph will drift a little, a couple points here and there but this seems really excessive.
I did a light no nute 5gal flush on both plants today incase of lockout, and runoff was down to approx.6 Im trying to get this figured out as Im overdue to flip to bud cycle, Im getting over grown. I was hoping I'd have this turned around in the past 2 weeks so I'm not trouble shooting in bud, but with this flush I have no choice but to make the flip and just go with what I got and hope I get it figured out before stretch is done.
How much drift is normal? How much drift are others getting? Could I be letting my soil dry out to much before watering?

[Bluey]

First thing to look at is what nutes and what pH buffers are you using.

The combination of these may not be compatible. Are you noticing a bad odour also?

Keep them from the same manufacturer is the first rule. That should work.

If not, mix up a solution with the suppliments you are using, buffer it to the correct pH and let it sit and test it daily to look for swings. If you get large swings there is your problem. Change your suppliments to match your base nutes.

[MrMagic]

There have been no funky smells ect.. and I have been using grotek nutes for over 20years and Root Farm Ph buffers pretty much my whole life. I had this same issue last grow as well in late veg. Note: My apartment has very hard water and a Ph of 9, but its never been an issue since 2019 (legalization). The only change that has been made on this grow is my buffer. My thought was my buffer went past its shelf life so I went to replace it with a fresh bottle, but I could not get the root farm for some reason (likely winter) so I went with Indo's ph down (Soft Water) This was highly recommended to my by several growers and local grow shop. I went with the soft water as it had the lower price and its just a watered down version of their normal strength buffer also recommended; so as to make smaller adjustments with soft water, hard water just uses a bit more. every thing seemed to be going fine up until just after xmas until I got sick and I couldn't get to them; they dried up dryer than a popcorn fart. I dumped in tap water to limp them through and went back to bed for another 5 days lol. I wonder if what ever is in the soil itself to lower the Ph is used up? (peat and...?). Grabbing at straws, looking at my notes this grow was started Oct 19. I know Sulphur will bring down the Ph but I have never worked with it for Ph management . I have Safer's Sulphur dust, but I use it as a fungicide/miticide. I've used it in the past for WPM and rust control. Would this be the same Sulphur used in soil? Im just spit balling and thinking out loud lol. I doubt id go that route.
Thanks for letting me bounce out thoughts lol.

[Bluey]

Try lemon juice, ascorbic acid, to bring down the pH. Dilute it at least 50%, preferably more, before adding to your nute solution. A 5 gal bucket of nute mix at pH 9 may require somewhere around 10 to 20 diiluted drops but I really have no idea until you try it. Add it slowly whilst mixing. Wait & measure. Just follow good practice for adjusting pH.

You likely have a problem with your medium or roots if it is not the new buffer you are using but I'd try ruling that out first since it's the only change you have made.

[MrMagic]

So I had some leftover feedwater that's 4days old now. Did a quick Ph check and 6.8; up from 6.3, I'd expect that just sitting in a bucket. So that tells me its reasonably stable. I did another soil sample and its roughly 6.7, and my probe is reading 6.9. I trust the soil test over the probe but they are close. So that's up by 0.6 since yesterday. Bluey I have heard of using lemon juice, do you think that would have a little more staying power? It just kinda came to me about adding some peat, but I wonder if it would put out to much nitrogen since I will be flipping to 12/12 any day now.
I'm also beginning to wonder if I'm just reading to much into it and am I underwatering? Which Im sure I am. I usually let it go until up to my main knuckle is dry, which with fabric pots I think may be to much. Going to the first knuckle seemed a little to much to me but maybe not. I also just come to find out that I might be mixing my nutes wrong. I mix in my base nutes first then my micro and finally buffer. Can it make that much of a difference to mix in the micro before the base nutes? If its that simple Im and idiot lol. I been reading up on light stress as well and I wonder if that could also be exacerbating the situation. I have heard that people running the vipar xs 1500 have had this issue. I have noticed my leaves praying lol. So I raised the that light to 36" and cut the power down to 75%
I managed to get a few pix today. As you can see in the middle pic, it just screams high Ph. Maybe yall can see something I'm missing

[Bluey]

Lemon juice holds my solution stable at 7 days, so if I do a mix at 6.2 it will be 6.2 in 7 days.

Lemon juice works perfect with my nutes and suppliments. It may do the same for you or you may find it is hopeless.

What pH meter are you using to measure your solution?

6.3 to 6.8 in 4 days is not good.

I don't recommend using peat in a medium because things can go wrong quickly as it has a very low pH. Many have struggled with it. You could do a search on here to find info about it.

[MrMagic]

Yeah I relish the idea of using peat lol. I have used it in the past with aquariums and its a pain in the ass to work with, so I figured it'd be the same with soil.
I just bought my first Ph pen 3 weeks ago when I started to struggle with this. Admitably its cheap, but it is all I could afford for now; its your typical vivosun. It was a bitch to calibrate but I think I got a fairly calibration, it jives with my drops when I compared the 2. Up until now I haven't really needed one. In veg I'd Ph down till it was just a little darker than bright yellow and not green and I'd know that I was just above 6 but below 7. When in bud Id Ph down so it was bright yellow and I know I was down to 6 and lower than 6.5. I got the vivosun meter cause I figured another tool in the box wont hurt, and I wanted something a little more accurate for tracking purposes. Side question. How long is the calibration solution good for once you mix it up?
I did a little more reading and I'm really beginning to think the main reason behind this happening is underwatering. My pics look very similar to that of others underwatered
Thanks for the telling me how to use lemon juice. I'm for sure going to give that a shot and see what happens. I will definitely be stepping up my watering practices and making sure I mix my micro in before I mix in my base nutes. (Cant believe I overlooked that lol meat head) I hope I get this soon, I had to do the flip to 12/12 today I so over grown that's gonna be my next problem lol
This sucks but I'm learning a lot lol thanks for letting my bounce ideas out there and thanks for all the input so far

[Bluey]

https://forum.growweedeasy.com/forum/growing-community/587080-the-tale-of-two-ph-pens#post587080