Wrong advice!
Dude in coco you should be watering every day till run off... ignore the other guy...
I would do the following
1 check calibration of your ph pen. I calibrate mine almost every week which is about every tank change.
2 test the ph and ec of the run off. This will give you a better understanding of what's in the root zone.
I would probably move the fan back. By putting the fan on the plants you are increasing transpiration and through this you ate increasing nute uptake. If you increase the heat or fan then you might need to water down the notes more. Given they are small I would flush through with perfect 5.9 ph low ec notes.... let it dry out for 2 days... then slowly start pushing up the strength.
Also.... use calming.... it's your friend in coco