today i did a gravel vacuum,i took out more water than was in the bucket(i had just used most of it to wash my filter),so i made more with the dechlorinator my mom had bought a couple years ago(and never used).it was after i finished that i read the label, "use before 05/11" how bad is this? i was going to buy pool filter sand for my 10,so i made it a double trip and got prime too,so if i need to i can do a massive water change to get it out(i really hope i dont have to).