hi guys i did a water change and complete tank clean over the week end fish out ,gravel change etc all was fine until monday night the water now smells i put a carbon bag into my canister to see if this would help with it but its now tuesday afternoon and still it ssmells any ideas???????thanx

Did you clean the filters as well?

no i upu the in let and out let into the container with the fish and syphoned water from the tank

Your water should smell a bit, like wet ground or something, but no foul odor anyway.
Does it smell rottun or what?

Your tank should smell a little bit but if it is strong then something is up. The cause is usually poor water quality, either lots of ammonia present or high nitrates. Can you test your water and post the results please. If your gravel was really dirty you may have stirred it up when you cleaned it and that is causing the smell. Either way do some daily water changes