I have never had a meter that would give me the same reading twice in a row. If I don't like the ph I just test it again and again until it comes out where I want it. I never trust 'em. Your ph swings don't surprise me. A lot of people have had successful grows just using the Lucas formula. It's always easier to follow the successful people. If you mix at that rate in tap water your ph should be fine.
My pH swings dont suprise you? What do you mean? I wouldn't call them "swings" as in they're up one day and down the next, they're just going down and that's the problem. I've had bad pH meters before but I usually run 2 meters just to reference them with each other. Lower chance of both being broken rather than just one.
Also if your plant is in grow or veg..move it to 18/6 or 24/7..I'm guessing you are trying to flower her right now with the 12/12.. Let us know how it turns out.
It's in bloom since quite a few weeks back. 12/12 is the light schedual.
Temperature should be between 18 and 22 c and the ph ideally should be around 5.5- 5.8. But a little more acidic is ok if water temps are kept below 24c..I found as soon as I went over 24 C the water started to lose oxygen even though I had two air stones (long ones) running full bore....from my power engineering exp..I can guarantee that higher temps with too alkaline or dangerous levels of acidity will kill the dwc plant grow..slightly lower temp around 18 - 22 c will be more forgiving on a move to the higher alkalinity..watch the plants for stem bleaching ..don't go over 6.1 ph ..I prefer 5.5 to 5.7..let us know what you find out..
My temps in water are usually around 21-22C. Dont have a chiller and since I dont run a rDWC it would be quite expensive to run 2 chillers for. Never had any issues with root rot, diseases or nasty smells during my grows - but hey, might've had issues that I just can't see or smell.
I wouldn't really check by a schedule, particularly the cheaper meters I use a fairly pricing Apera meter and although it never goes off more than .1 every blue moon I still check it maybe 2 or 3 times a week.
The cheaper the meter and the more inexperienced the grower the more frequently you should check and calibrate!
Some people have good luck with the pH paper strips though I've never used them they seem efficient as well, best of luck
I try to check twice a day, once before work and then directly when coming home. Mostly because of the issues i've had now with the pH dropping and I dont want it to sit in <5pH for more than needed. I've used Adwa AD-12 for my pH measuring for 2 years now but since they usually only last a couple of months (even though i'm very meticulous in taking care of the probe) and no answer from the CS department made me switch to HM digital. Sure, it isnt the most expensive meter you can buy but I feel I dont need that amount of precision. Just need it to dial it in.
As a general update, found one of the leaves that looks like this.
Any thoughts on what might be the cause? This is from the bucket that's been holding quite steadily at 0.7mS and a pH of around 5.7. Gave it fresh water today, perhaps a gallon and no pH adjustment.
The other plant, which is fluctuating so bad, is still dropping quite hard (the pH) but not showing a lot of bad signs on the leaves, unlike the otherone which is the opposite.
