At first thought it was Calcium deficiency, now idk whats the problem :,). White Widow 23 days since germ.

boiling point of vinegar is a bit higher than h2o, which would correlate with a roughyl similar evaporation rate, which is actually quite ideal. I've taken actual chemistry classes, lol... Acetic acid is perfectly fine to use as a pH down. You canassume 100% disassociation with it. pH drift is not caused by using acetic acid. pH drift occurs with unbuffered solutions and 'organic' products, lol. Adding it blindly without testing what you are lowering it too is not wise. If the tap + ferts is consistent, then it'll take the same amount each time. Measuring once is all that is required in that context. pH strips are cheap for 100... it's cheaper over time than the pH pens and stock solutions etc. Just get the 4-color, .5-resolution type. yellowing from tip-in and starting lower on the plant is a sign of nitrogen deficiency, but i don't think that's the case here. I see 2 different symptoms. Judging based on leaf symtpoms is not always 100% correct, but fairly certain there is no N-toxicity here. The leaves would be far, far darker, which would also creep up from bottom as it progressed and you can plainly see that has not occured. I'd figure out what you did to the pH before messing around with changing your formula, expecially if the recent issues immediately followed a blind application of likely 5% white distilled vinegar (acetic acid). Even if the tap pH is 8.4, you'd only need a few mL of 5% acetic acid to drop it down near 6.0 to 6.5. So, if you added more than 2-3 mL, you likely acidified the memdium too much. I suspect your watering habits are contributing to the problem too. You do not choose a volume of liquid to give the plants. You give enugh water to get the entire thing wet - little runoff is fine in soil and if soilless you should get a religious 10% or more runoff waste water. Can toss it outside but not for potted plants. Wait for top 1" to dry, then repeat in soil. Some soilless media need a faster trigger. Feeling weight of the pot will be a consisten metric as that directly relates to how much water you need to add -- it is predictable but only in hindsight after your first irrigation. If you use the same substrate characteristics, it'll be the same in future too. If you weren't doing that, start doing so... and figure out what you did to the pH ... this can cause all sorts of issues with nutrients even if there is a healthy amount present. those look like 2 different symptoms and not quite adhereing to typical progression, so rootzone / pH becomes more likely to be the cause than an imbalance.