quick question about salt water

hi there i made my salt water on wed to do my normal wc but because one of the fish had a prob i got told not to do wc so fish didnt get stressed out any more



now its i am going to do the wc tomorrow



will the salt water i made on wed be ok to use still

its been in a big bucket with a power head to keep the water moving and a heater to keep the water at the right temp



and been covered up



tia