Dr. Who, you're not entirely right. EC (ppm), i.e., fert content is what drives the pH level. It takes a lot of patience to read through this argumentative thread, but it looks to me that not only is the grower not helped much by this, but anyone who has the patience to read all of this and is naïve about growing, will be misinformed. This is so common on this site and other message boards, where persons who are aggressive writers make their argument in a way that it becomes impossible for naïve readers to be unable to determine fact from b.s. fiction.
The problem here is 6 tablespoons (!) of Beastie Bloom, or whatever that added fert was. This was the mistake. The pH argument really isn't all that valid because chasing the pH issue when your fert content is bad might help some, but won't save the plants. In fact, there appears to be so much damage that unless quick action of dumping the res, getting a ppm meter and using a level of fert that promotes health rather than destroy it, the plants will continue to die. PPM drives pH, not the other way around. Adjusting pH might cause plants to appear better initially, but in the end continued high loads of fert will kill plants. You guys seem to miss the point where the OP wrote they gave 6 tablespoons in 25 gallons, apparently doing this carelessly and had no clue what impact it might have. Now they know.
Dr. Who, if you are an organic farmer that's nice and all, but I'm not sure this qualifies you to make comment on hydro grows. No offense, but when I read your posts you insist on certain issues that seem to be based on what people on the web have always asserted: fix your pH and all problems will go away. Since ppm drives pH and not the other way around, please know that fert content in water creates the characteristic of pH. If a grower needs to fix pH, adjusting it isn't really a good answer, especially so in hydro where it's easier to dump the water and start over. Hydro growers should focus on ppm first, get that right for the age of the plant, and then check pH.
The plants were poisoned with high fert load. If the pH dropped too low, this will make matters worse and damage happen more quickly, but adjusting the pH isn't the best solution. In hydro a ppm meter might be more important than a pH meter. Get the ppm right and you probably don't have to worry about pH much (although keeping an eye on it is a good idea, just to be sure it's okay).
Soil grows don't usually need as much watching over as hydro does, especially using ebb and flow or aeroponics. If you want to grow in hydro, DWC is the way to go cuz you'll see fast growth without having to watch it 6 times a day. E&F and aero allow more oxygen to get to the roots which enhances nute uptake to a great degree and if you don't know what you're doing, you will kill your plants just as fast as poisoning them with high fert loads like 6 tablespoons.
