How long does stagnant SW last?

[rcoapstick]

I bought a 5 gallon bucket from my LFS and havent used it yet. They told me the water goes bad if it stays stagnant too long. What causes this? and how will i know if it is bad. Its been sitting in a cool dark room for like 5 days. All water parameters check out. The pH was a little low, but I am currently aerating the water so that should come up soon. Any insight on this?

 

[sasquatch]

if its ro/di new mixed it should be good for quite a while, if its tank water maybe 2 hrs? there is nothing in new mix to go bad, if exposed to air bacteria might start to grow, no worse than a storage bin of water

 

[yankieman]

from what I have heard water actually gets better with age as long as its not been contaminated by anything

 

[PIMPALA]

lol. it doesnt go bad. just do what you're doing, and keep a pump in it.