Q. How often should I do a water change?
A. Water changes are important to re-balance the mineral content and to dilute excess accumulated nutrients. In our experience more frequent small water changes are more beneficial than infrequent large water changes. It is less disruptive and eliminates the see saw of water quality parameters. When performing a water change it is important that the new water match the removed water as to spec. gravity and temperature. In essence the water coming in should be perceived by the fish and or corals as no different (except as higher in potency of trace minerals) than the water you took out.

Again, in our experience, small frequent water changes really can ease the pressures of proper tank husbandry. It is important to log your water parameters so that the tasks you perform, including dosing, water changes, etc. can be qualified and tracked.

If you are having water quality problems, perhaps excess algae, beware that water changes with tap water can actually exacerbate the problem. Use a verifiably pure source of water such as reverse osmosis and or deionized or distilled water.

A good rule of thumb for frequency is 5 to 10% water volume change every two weeks. Your test results should dictate the frequency of changes. Remember that it is more difficult to correct a problem than it is to eliminate one. Action is better than reaction.