Most important for your new freshwater fish tank is changing the water.

Why? Well, water changes involve more than just removing water from the tank and replacing it. You have to consider the condition of the water you are replacing it with, and the amount of water to remove. These can affect the water quality, and the state of your aquarium's health.
Colonies of beneficial bacteria grow on every surface in the tank. These bacteria are part of the biological filter; allowing them to thrive will help improve the quality of the biological filtration system.


- Coffee table aquarium
- WaterWonders Aquarium Kit

Every time you clean you fish tank, you should remove 10-15% of the water and replace it with fresh, dechlorinated tap water (bowl and small tanks need larger water changes more often). While you are doing this, you should use your siphon to vacuum some of the debris collected in the gravel. If you have an under water filter it is very important to clean the gravel when you do your water changes every week, or every other week, and this will remove waste particles, and oxygenate the substrate as well, allowing nutrients and oxygen to reach the biological bacteria living on the gravel. Usually, you can clean 25-33% of the gravel when you siphon 10-15% of the water.

Just some notes:
-Use a gravel cleaning siphon whenever you do a water change to remove all the trapped particulate from the gravel and also remove dissolved pollutants.

-Although I love to use the auto-filling siphons and so far I have not had any problems, be aware that adding untreated tap water into your tank can lead to disaster. You might prefer to precondition the water before adding it to your system.

-Always use water at room temperature, never use hot water to adjust temperature. Hot water contains a greater quantity of heavy metals like copper and lead. Heavy metals can be removed from tap water by the addition of "slimy" water conditioners. These products contain chemicals that will bind these metals, rendering them harmless. Carbon and certain resins will also remove heavy metals from the water.

-It's better to do smaller water changes more often than one large water change. Doing this will keep the water quality from changing too drastically.

-You can change the water during cycling. Normal water changes will not affect this process after 2-3 weeks.

-Always allow your tap water to run at least five minutes before using it. This will help decrease the dissolved heavy metal content.
Happy fishes!!

From : ezinearticles