There are a few parts to aquarium maintenance and keeping your aquarium clean. The most important is doing regular water changes.
How to do a water change:
A water change is typically done with a siphon. A syphon can be purchased at your local pet store and it is basically a plastic tube. The tube opens wider on one end, and that end is moved through the gravel to pick up waste materials that have gathered in the gravel.
You will need a bucket for this job as well. I suggest a 5 gallon bucket from your local home improvement store. These are cheap and effective.
First place the wide end of your siphon into the gravel of your tank. Take the smaller and and create a vacuum by sucking water up through the tube. Try not to get any in your mouth! Once water is flowing, it will continue to do so until your siphon starts to suck air.
You want to remove roughly 25% of your water when you do a water change. I suggest doing this weekly or bi-weekly. Only take a maximum of 50% of the water out of the tank. If you take more than this, your fish may not be able to adjust to the change.
When adding new water, make sure it is the same temperature as the water already in your tank. I also suggest using water conditioner or dechlorinator on the water before you add it to the tank. This will prevent your fish from losing their vital slime coat and prevent fish disease.
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