how do you properly clean aquariums?

Here's a link to a web site that covers all the details quite well. The only thing I differ with them over is I prefer a bit larger water change each week and suggest about 25%, but that really depends on the tank and the stock levels.

http://www.firsttankguide.net/waterchange.php

MM

You need a gravel cleaner if you don't already have one.You should use this to remove about 20% of the water once a week.Use tap water treated to remove the chlorine not distilled water.You can just pour the new water in as soon as your treatment has dissolved but try to get it around the same temperature as the water in your tank.Make sure you unplug your filter and heater for about 15 minutes before you start as sudden temperature changes aren't good for the heater .

ok u can leave tap water in the tank for a couple of days i would say about 3-5 days and you can even put all the stuff in there then put the fish in there and then scrub the filter. if u dont want to go through all that trouble u can just put tap water in the tank and add a chemical called stress coat u can add right when u put the fish in the tank or right after but make sure u read the amount of stress coat u need to put in the tank on the back hopefully this helped!

I am guesing you have a fish tank and you have some fish in there and you also have a filter. First of all remove about 20 percent of the water, wipe off the little salty build up off the glass and on top of the light. Put water in a bucket equal to the amount you took out, put dechlorinator in and slowly put it in your tank.