Mildew on Walmart grow bags

[Stoney Roads]

So I am growing with Walmart grow bags and I am seeing what I think is powdery mildew on the bag. My plants don't have anything on them and I'm not sure that that's what is in the bag. I need some input from others that have grown with the Walmart bags. The color of them is blue of course it could be just from the coco because I am in 100% coco. I am starting to get worried my girls are going to get ruined

 

[thebudking]

I would guess it is salts from your nutes but a picture is needed to really tell.

 

[Stoney Roads]

I would guess it is salts from your nutes but a picture is needed to really tell.

I will take a pic in the morning when the bags are dry that's when you can see it. I didn't think of salt build up though that makes sense

 

[Stoney Roads]

so here is a pic of the bottom of the bags what do you think

 

[KNK01]

mine look the same its just the nutes. your plants will be fine.