@TommyD I had similar problems but I did not burn them . I have a very different approach than most on how I manage to raised plants. I feed from the drain pan and maybe water in from the top once a week , which is working pretty simple for me . I stop trying to match the runoff numbers to my watering , but I’ll feed close to the runoff number if that makes any sense 
? Plus I try not to let my medium get to dry except maybe the top layer since I’m running 2 types of organic soil mixed , I try to simulate what an autopot does automatically . Now it takes a little finesing but from the last 2 grows with what I was doing to this Auto grow has been so simple so far this way verse the other way .
I mix up a full gallon and I used a 16 ounce bottle to pour it in , and all I’ve done this grow was keep enough nutrient feeding in the drain pan at all times so it never dries completely and to my surprised it worked effortlessly for me . The other pot I mange to grow it hydro and had no clue I was even doing a hydroponic style grow , Now in veg I only pour in 16 ounces until the plants start growing vertically usually means the roots have made it to the bottom of the pot , once the plants shows vertical growth , I start light feeding from the drain pan and water in my plain water . I think this way allows most of the salts to get filtered out instead of building up in the soil cause the fabric pots acts as a filtration system I believe in a way I think from my comprehension but I’m no expert I’m not a grow pro , but I do know how to grow healthy strong plants and even though I break rules a bit , I still get huge full plants that grows with no defiencies are hardly any tip burning , but I feed the roots from the bottom and I water in the organic life in the soil with seaweed , recharge but I try to measure how long it takes the plants to wick up 16 ounces of water are food and judge it from that but I never let my drain pans get dry doing growing until I’m ready to do my plain watering from the top if that makes sense it’s what I do and it works flawlessly. Here is my first cut 
off the oldest OG kush plant that’s maybe less than 7 days to finish I think but it took almost 9 weeks to start pre-flower , so I’m just glassing it , but I always get a first cut around 5-10 % amber to see it it’s good there are need more time .
The picture plants looks like magnniesium and phosphorus issue from either to much calmag are not enough , and serious ph not being consistent for the right nutrient uptake are the grower did not transition the feeding from veg to bloom , looks like the plant had sudden changes and ph swings and inconsistent ppm to me but I’m no expert , are proclaim to be , I just spend to much time reading and talking with plants.