Problems 😭😭

Hi everyone, can anyone help out please. My leaves are going like this. Its happening from the bottom to the top of the plant. It started on the serrations of the leaf and then moved inwardly. I stupidly measured my res wrong and was either feeding excess calmag or excess base nutes for around 2 week (I can't remember which way round) I habe corrected my mistake and lowered calmag to 0.1ec as I first thought it was PK being locked out due to the calmag.

Barneys farm Blue cheese Week 6 from flip/4 week from seeing the start of actual flowers a 5 week veg Iws trident recirculating sysyem in clay pebbles 16l pots which are flooded 4 times a day 4hrs apart for 7 minutes each flood (pots fill within 2 minutes) Very soft tap water 0ec Ecothrive neutralise Using plagron nutrients Plagron hydro A&B Plagron hydro roots (finished last week) Plagron power buds Plagron green sensation I thought i was feeding ionic calmag pro at 0.4ec Bringing the total ec to 2.2-2.4 like i say though, this could be wrong and it was more than expected and less nutrients or less than expected and more nutrients. (I THINK) it was less than expected and more nutrients. I was getting burn so I flushed reassessed, got the volumes correct and then started again on 1.9ec nutes with 0.1ec calmag with plagron calmag pro Bringing the total ec to 2.0 ec runoff doesnt really move. 2.1 after a week of use. I was also using silver bullet with the nutrients until it had a reaction when I started green sensation. Ph swings daily from 5.7 to 6.1 and back again in the morning Temp is 24c lights on 21c lights off. Rh is unfortunately 60% im unable to get it any lower Res temp is 18c I have 2 air stones and a circulating pump. Lighting is 3 led lamps which gives each plant around 700-750ppfd Plenty of fans inside the tent too. Sorry if it sounds mumbled, im high as a kite