just filled a 75 gal tank my question is that i use 30 gallons of water from my old aquarium and 20 gallons from a friends tank both have been up for over a year and 25 gallons new water all the water that was used and added all the levels are great so after the water clears up would it be advisable to ad fish i have them in a 10 gal tank for the time being and if so i would check the levels daily for about a month a do water changes as needed thanks