Weekly Routine
Since the water in your aquarium is stagnant, it needs to be partially changed as often as
once or twice a week. Water will build up large residues of waste, dissolved gases and
debris if left unchanged. When you replace a little of the water with new water, you are
effectively reducing the total amount of waste concentration in the aquarium.
In a regular aquarium, nitrate and nitrite is the primary source of toxin. Since fish excrete nitrous wastes, the nitrate and nitrite build up in an aquarium with a large
number of fish can be quite high even after a short period of time. Regular water change is the safest, surest and cheapest way to detoxify your aquarium. If you have used medications in the water, these also will need to be removed as soon as their presence are not longer required. You should not leave ANY unwanted chemicals in
the water of your aquarium.
There are two important factors that decide how effective your water change will be: The frequency of the water change, and the percentage of water you change each time. The overall effectiveness of the water change is dependant on the amount of water you change in a period. One water change should however never be very large. When there is a sudden change in your water quality (pH and temperature etc), the fish in your aquarium will be subjected to stress. If your aquarium water has the same pH, temperature and hardness as your new water, then changing up to 50% of water at a time will not stress the fish. If there is a significant discrepancy in pH levels, temperatures etcetera, changing large amounts of water may stress your fish enough to even kill them. During emergencies, it can still be necessary to do large water changes quite often. In some cases, this is the best line of defense as it would be more stressful for the fish to stay in the unsuitable water.
To facilitate this, you need to get replacement water that is as near a match to the existing water in the aquarium. Another factor is that in the course of time, the water in your aquarium will tend to change its chemistry a little. Thus, it is necessary to keep a check on your water chemistry every time you make a change. You can push the acidity of the water up or down by using non-inert materials like crushed corals, rock etc, or through the use of certain chemical additives. How frequent should the water change be? If you can change the water more frequently
