7.2 ph is way too high for coco, aim for between 5.2 and 6.2... around 5.8-5.9 is best. Get some ph down from the hydro store, or you can use lemon juice as a quick fix... but definitely get the ph down and some ph up also, meant for plants (not for aquariums!).

From now on, always ph your water before feeding. Surprised your other ones aren't having problems yet, but I'm sure they will soon also.

Forget the CalMag part since your using tap... Another good measure is to let your tap water sit out for 24 hours to let the chlorine evaporate from it. Might not be the problem, but it won't hurt to do it either.
bigtopsfinn Reviewed by bigtopsfinn on . New to this...should I be concerned?(pic) Hey I just got my mmj card and set up to grow so I am very new to this and I am concerned about what my 3 s. diesels are doing. All 3 look the same. No other plant in my room looks even close to this. I'm using canna coco with the canna line of products. I'm growing in smart pots. I water when I feel the pots about as light as a pot with just coco no water. The plants are under a 1000hps enclosed light at "24 above with inline ducting and fans to cool. Room temp is a steady 76 degrees Rating: 5