hi...got my first bottle of liquid about a week ago - I've been refilling the carts I got with the ecig, 3-4 drops and 1 on the atomiser. All good up til now, just noticed though that the gauze is turning brown almost immmediately...the retailer advises not to use them if this happens. thought I would get a few more refills out of them? I only vape in the evenings...I'm not burning out another atomiser already am I??