Every Grow- At the end they do this?

[Mañ'O'Green]

I have this too but am in soil. In my opinion, the burnt tips and dark green non affected leaves shows a toxicity. I have not fed more than 3g per gallon and still got this toxicity. Not all plants behave like that though. The toxicity locks out nutes and screws with PH, causing this to happen. Only thing that don't make sense is that you are in hydro. If your oxygen pot system uses a fabric pot and your medium is soil or similar, I am betting its a lockout from salt build-up. Check your outer fabric pot when its dry. Do you feel the coarse salt build-up at bottom? Is your runoff ppm really high? If so, you might need to feed plain phed water for a while. I see improvements in as early as 24 hours when i do that. Except mine is not ebb and flow so i water to runoff.

If you're not using fabric pots or soil like medium, forget everything i said lol

I think you may be on to something here. I know when using rock wool cubes in flood and drain you must flood above the entire cube or you will get a toxic salt build-up at and above the water line inside the cube. Well maybe there is a salt build-up on the hydroton?

I am running hydro (rock wool cubes drip to waste) with MegaCrop 2.0 and NPK Industries RAW products along with B1, kelp, humic acid, Si, yucca. I am still dialing it in. Check my Mixed Autoflowering Strains for what I am doing this grow. I use MC as the base and make adjustments with additives for the stage of growth the plant is in. My last harvest was very high quality. I am still chasing the grams/watt numbers I hit in DWC but I am getting close ~1.67/GW The StarDawg tested at 22% THC it is too expensive to get the terpenes done but they are amazing to smell.

 

[Simplicio]

This used to happen to me with other fertilizers until I started reducing feed in flower.
Plants don't need much food when they aren't packing on weight.

Maybe you ppm pen is off.

I also had bad luck with tap water, and there's no telling what those ppm are, or whether there are non-salt compounds in it.
I tried tap water for a couple weeks, and the plants didn't like it, so I got an RO system.