COCO COIR Can anyone help diagnose this

[Pukapies]

Can anyone diagnose this

[D.A.A.S.69]

Morning Puk, looks to me like she's dried up, or burnt up, damn near.
How have you been watering? What kind of light are you using?

[Campesino]

Just flush now. Worry about whether you have to cut or resume feeding after seeing the response

[Pukapies]

Cheers camp.. should I use a flushing nute? I usually use canna nutes and I have seen that they do one? And also do you think I should flush the rest just to be on safe side? Got another 3 but they all look fine

[Campesino]

Yes, if you have a flushing solution, Not sure what Canna's is... I use FloraKleen by GH, Use it!!! Absolutely
I would want to know the run-off and inflow EC values on the others. I can give you a lot of advice about how to manage the Coco, but it all depends on knowing EC. I discuss flushing based on EC in my guide also.
But I don't need to see a meter to know that the EC of that one is way too high, so a good flush with agent and then resume fertigation (12 hours later if using flushing agent), probably with weaker nutes and more run-off than you have been running.

[Campesino]

"Nute" Burn!!! EC is too high
FLUSH FLUSH FLUSH

May benefit from reading my Coco guide link in Signature

[Pukapies]

Thanks guys.. got 600watt hps.. 4" intake 6" outlet in a 1m x 2m x2.4m tent