High TDS and low ph runoff - Lockout? deficiency?

@sir_isO @Hempkid @B4RNS thank you all for your suggestions. I always make sure to have decent runoff so doubt its a build up. I wish I used dedicated cannabis soil which would reassured me things are okay. But having used a random mix of potting soils I decided to go for a proper flush as it seems like my plant struggled to uptake nutrients when there seems to be plenty. Also the ppm value started going up again so to be on a safe side, flush was the wisest thing to do :) thanks again

Oh you may want to disregard what I said, as I checked in your diary that it kinda stabilized lately so it's probably getting there in terms of normalization.

If the water going in is 7.4 and the water coming out is 6.0, I would guess the medium is likely fairly acidic (as in <6 ph).... I'd probably add some calcium, magnesium, potassium and carbon buffering (like maybe a combination of potash/char, epsom salts, calcitic lime).

It’s because you don’t pour enough water thru the pots when you water your plant. When you water your plants, try to get 20% of drain coming out.