A bit of a problem with Aeroponics (Newbie)

I have setup a DYI Aeroponics set with PVC pipes. My plants look like they are dying, but two are not. I started germinating the seeds and then put them in rockwool when roots would show through. I would mist them about 5-6 times a day with 6.5-6.8 pHd water. 24 hours before the transplant, I've forgotten to mist them and the leaves started to turn yellow. I'm assuming because from the lack of water.

So its been about 48 hours now and they are still yellow. I constantly check the pH and try to keep the pH down between 5.5 and 6. When I had just the water and 25% nutes, I had ~750 ppm. After bringing the pH down, the ppm jumped up to ~1200. Next day I had to use pH down again and poof, the ppm increased to ~1600.

I know as a general rule of thumb is to keep the ppm below 1100 during vegetive stage and bump it up to 1200-1400 during flowering.

Am I wrong? Am I misunderstading something here?

Pictures 1-3 are my AK47s, and 4-5 are bagseeds.

Well, it's the old good news/bad news thing.

The bad news is that you've got several problems...

The good news is that I'm answering your post.

First off, you're spraying your plants too often. Spraying with water leaches the nutrients from the leaves. So without nutes stored, they turn yellow, kinda like overwatering.

Most important in Aero is res maintenance. The proper pH range and the ppm must be maintained, because there is no medium to buffer the nutes for the plant. Regular topping off with plain water will keep the ppm in line, and a pH monitor will help with keeping that in check.

HTH