Zu viel ph down

add a base.. don't buy "ph-up" products as it's some common household ingredient or similar and priced 10x higher than buying it in a different package. look at ingredients of any "ph-up" product sold to marijuana hobbyists, then go buy that ingredient much cheaper in a product not targeted at hobbyists, lol. Any base will work. Even baking soda won't add enough Na+ to be a problem for any single grow cycle... Maybe not a good idea for a mother plant that sits in the same pot for 1-2+ years. ph-down is easy.. white distilled vinegar is a great optiont hat doesn't add anything that impacts nutrient balance nor Na+. I've never had to raise the pH so i'm have no go-to suggestion, but baking sode is fine in the short-term.

How much extra PH Down fell into the solution and how much do you normally use? How big is the volume of water your working with? All questions that will help If you added to much PH down you can try and raise it with PH UP. This is not ideal but it could work. it will increase the EC. The best solution is to make a new batch, this is sometimes difficult with 20Gal Reservoirs but a small bucket is not that bad. Or dump half out and add in fresh water, it might help bump it back up.