My husband bought a salt water (60 gallon) tank from someone, and emptied the water and left the sand in it when it was purchased. He had it in our garage for about 7 days, he brought it in and set it up, started adding the water and salt into thetank, and our whole family started sneezing and having sinus problems, and the tank kind of smells. Could the sand have mold, could that be what is making us feel like we have allergies and sneezing non stop? we ve all had to take allergy medicine and Mucinex and it s still bothersome.