need some help please

[jjbbambam]

hey all joe here i was wondering how long does it take for a fuge to start reducing the nitrate level in my tank. i have numerous amounts of water changes and it still seems to be the same i just bought one of the cpr hang on fuge and it all up and running with mangrove chloe and mirical nud and the the let mel said to get. i have a 55 gallon reef stocked with coral and fish my amonia level is 0 ph is fine and all others ar fine as well i think the reason for this i had made my sump a refuge and had lettuce calurpa in it and i went a way on buisness for a week ant the timmer failed so when i got home all the lettuce died and my live rock was fine and all the live sand i had was all brown so i took all live sand out and threw it all away when i stured the water it was all brown so thats why i did it. is thier anything else i can do to help get the nitrates down to like 40 its 160 now. thanks joe