First Grow Problems

Hey guys, I'm pretty much a noob and have some newly transplanted clones showing some issues. I transplanted them 3 days ago into a coco hydro system. Watering once per day with RO water and using GH Cocotek at 75% of the feedchart 330ppm. I am not currently using any CalMag because GH told me from an FB message that none should be necessary. And now going into today I am seeing this. I am also running about 1000 watts of LED 24 inches above @18/6.

PH has been around 5.8
ppm: 300ish
water temp: 78
tent temp: 85
humidity has been as low as 25% but usually around 40%

cocotek grow a&b at 75%
rapidstart @ 1ml per gallon.

Is this mag deficiency, nute burn, over watering? it happened so quick.

Any advice would be greatly appreciated.

Thank you

How big are those bags & how long have you had them in there? They appear to show signs of low RH, any reason why you water in at 78f? That's a bit high imo, for small clones in a hot dry environment you might try to water in at 70f.

I would have to agree with SPLFreak808, Water is too warm, try to keep it just under 70f. Also anything you can do to boost the humidity will help. I set my dehumidifier at 55 and let it go. Sounds like you may need a humidifier.

Thanks for the replies. They have been in these 3 gallon oxygen pots since this Sunday. 3 days. They are clones that we purchased and brought home Friday. I'm now questioning whether or not some of this already existed. But I don't think so. Is this something that can happen this quickly? or would it have to be pre-existing. The clones were grown in soil. Transplanted to coco this Sunday.

The water is at what it is because that is the room temp of the building. This is an ebb/flow res oxygen pot system. We are flooding once a day for 10 minutes in coco : perlite 3:1.

Are the tips a sign of nute burn? And do the brownish streaks on the leaves look like mag def? Like i said we are using RO water and i was all set to begin with calmag to about 100-200 ppm then cocotek @ 75%. But skipped the CalMag because GH told me to on their messenger. I'm thinking maybe I should have started off with CalMag to 100-200ppm since we are running RO water AND coco, and then maybe 50% nutes.

We've also made some adjustments and now are running at about 50% humidity.