Waht you will need:
1) You will need a clean 5 gallon bucket that has never had chemicals or soap inside of it.
2) A hose or gravel cleaner
3) A bag of natural or synthetic sea salt
I have split the work into two parts the tank which needs to be cleaned ever week on the same day and the filters which can be cleaned every 2 or 3 weeks.
The very first thing you have to do before you start cleaning your fish tank is to unplug your tanks heater if you have one. The heater can not be allowed to be removed from the water while it is hot so make sure to leave it unplugged at least 20 minutes before attempting to remove it. The water help cool the glass on the heater if removed it could crack, or the glass could totally shatter. You should also remember to never stick your hand inside of any fish tank before making sure the heater is not only off but unplugged from the wall. A small crack in the heater could be more then enough to cause a shock to you that can be fatal.
After the heater has ha time to cool you can safely remove the heater from the tank or it the heater is submersible you can just push it down to the bottom of the tank.
Now take any decorations you may have placed in the tank, so all you have are the small gravel at the bottom, this will allow you to get any dirt that those decorations may have been covering up. Now if you do not have a gravel cleaner you are going to have to roll up your sleeves and get your hands wet. You will need to stir up the gravel to get the dirt that has settled between the gravel into the water, and start removing the water into the bucket with the hose. Do not throw out the water you will still need it to clean the filters.
If you have a gravel cleaner, push the plastic tube into the gravel until it hits the bottom of the tank, then start a siphon into the bucket, every second or 2 move the gravel cleaner over an inch or 2 and repeat this process until either you have removed 15 percent of the tanks water of you have cleaned all the gravel.
Now at this point you can clean the Aquariums filters. The insides of the filters are used to grow bacteria, that help break down the nitrites and nitrates that are in the water from fish waste and uneaten food. To make sure we don’t kill all these Aquarium friendly bacteria, we clean the filter materials and sponges in the dirty water that I also full of the bacteria. Take everything out of the filters and rinse them of in the bucket of dirty Aquarium water, then give the sponge a couple of squeezes in the bucket and reassemble the filters, and put them back on the tank.
Now before adding the water sea salt must be added to the tank. All water has some amount of salt in it and to replicate the natural habitat of the fish there must be salt in your tank as well. Add approximately 1 cup of sea salt for every 50 gallons of water.
Now you can add water to the tank, but you must make sure the water is the within a degree or two of the temperature of the water in the tank. A drastic change in the tanks temperature suddenly can throw the fish into shock and kill them or weaken their immunity and help give them a fish disease. I recommend filling the bucket with hot water and checking it regularly till it is the same as the tanks temperature, then slowly add the water to the tank, start the filters and the heater.
Cleaning the filters only needs to be done once or twice a month, but the water in the tank must be cleaned on the same day every week.