How to do water changes.

Please share you opinions and suggestions. No one will flame you for asking basic questions here. This is a site for aquarists of all levels of experiences.

Everyone with a fish tank has to do water changes, but many don't know how or when to do it. So here's some tips and suggestions on how I do them.

First thing is deciding when to do the first water change. There's no general rule or number of days. It depends on water quality and that can only be determined by a water test. For new tanks, test the water twice a week, and then determine if a water change is necessary. Once the ammonia levels exceed .25 ppm in the test, its time to consider performing a water change. Miseducated hobbyist will sometimes suggest not doing a water change till the tank is cycled. Either they don't care about the lives of the fish in the tank. Or are unaware the harm that the ammonia is doing to the fish and the high mortality that will result from it. The best way to cycle a tank is the "Fishless Cycle Method" it's faster, doesn't harm any fish, and capable of growing enough bacteria to handle a large bioload right away if done correctly.(Thread about fishless cycle coming soon) water changes during the cycling process will not prolong the duration of the cycle. Its a myth that is passed on because hobbyist don't understand what the cycle truely means. (Discussion for another thread, not this one)

How much water to remove? It depends. We all want to believe that there's a magical percentage or number of gallons that need to be removed, but it's complicated. It depends on several factors. Here are three that I will focus on: fish species, tank's water volume, and test results. First, goldfish do not require the same water change schedule that discuss require. They are hardy fish and can survive in harsh toxic water much longer than delicate fish can. Just because they can survive harsh conditions, doesn't mean they should be subjected to them. Keep the ammonia, and nitrite levels at zero ppm at all times. The nitrate needs to be kept near zero. Or between 5-10 ppm for tanks with real live plants. The pH will depend on the fish species, and so will the temperature. Most common pet store fish don't require any special levels for alkalinity, hardness, and other less useful test kits. If you get any delicate fish or livestock, be sure to fully understand its requirements and to test often. Now that we know what to test for, we can then determine when a water change is necessary.
Got ammonia or nitrite? Do a water change every other day till its at zero.
If the nitrates are high or the pH is low, follow these suggestions. First perform a 25% water change. Don't perform a large water change right away because you may shock the fish and kill them. The smaller water change will help adjust the aquarium water to the clean water source. Test the water a day later. If the test results are still high, then perform a 30-35% water change. Wait a day and test the water. Continue testing the water and then perform a 50% water change. Never do more than 50% water changes unless it's an absolute emergency. Only experts should perform larger than 50% waterchNges on the typical fish tank. Or if its a betta bowl. When the nitrate levels are very high to begin with, it will likely take several 50% water changes to bring the levels down to acceptable levels. It shouldn't take very many water changes to bring up the pH. So if the pH is still low after several water changes, try using a pH buffer to raise and maintain the pH to a desired level. chemicals such as "pH Up" should be avoided. Look the "buffers" to help maintain stable pH levels.

Once the water parameters are within acceptable levels. You'll need to develop a maintenance schedule. This is done by choosing a percentage of water to remove and deciding how often to remove it. Please note, adding water to a tank is not a water change! I suggest starting with water changes every two weeks and continue with the above mentioned 50% changes. Please read above before jumping into the 50% changes. Test the water at least monthly. I recommend testing twice each month. If the test results have not changed, then smaller and less often water changes can be done. If the test results at any time get worse, then you will need to increase the frequency and never exceed the 50% change. Increasing the percentage above 50% to compensate for frequent water changes, is a poor practice.

Now that we know how much and how often to perform the water change, let's discuss how it's done.

We will discuss the gravel vacuum or also know as syphon method. The benefit of this method, is that it removes waste that is trapped in the gravel before it decomposes and turns into ammonia, nitrite, and finally nitrate.(There are other chemicals produced and consumed when waste breaks down but that's beyond the scope of this thread) Several sizes and styles are available on the market, but the idea is the same. There is a wide tube that sucks up water and waste, but not the gravel or sand. Some syphons are easy to start while others require some work. If you understand how to syphon gas out of a tank, then you can start a gravel syphon. I hope to have a video soon demonstrating the way I do it. Much easy to show how it's done. I'm sure most readers would not understand my writen description with out some visual aids.

Once the syphon has started, be sure to control the flow. If the flow is running too fast, you may not be able to vacuum the entire tank before using up too much water. If this happens, don't worry, just place an indicator where you left off and begin there on the next water change. It is not critical to reach every last spot while vacuuming. Just focus on the dirtiest locations. Such as under large rocks and decorations. Move the decorations while vacuuming instead of vacuuming around the.

Never remove the fish from the tank unless its a betta in a betta bowl. Handling the fish is very stressful, and likely to cause harm and even kill them. Don't worry about sucking up the fish. They are generally fast and will stay out of the way. If a fish does swim into the tube. Just pinch or kink the hose to stop the flow, and let the fish out.

Important information!

Caution with heaters. I suggest placing a submersible heater horizontally and as low to the gravel as possible. Placing it vertically is incorrect and may allow it to become exposed to air. Heaters outside of the water will get very hot and possibly burn your hands if touched. They are likely to explode and shatter when water touches the hot glass tube. They may also leak and create a shock hazard once water reaches the electrical components inside. The safest suggestion is to unplug the heater while performing water changes. But remember to plug it back in once you're done. Set a reminder if possible. Many people forget to plug the heaters back in and wonder why the fish get sick later.

Tip.

When performing large 50% water changes. Its best to let the water sit out over night in open air containers. This allows the trapped gasses to exit and helps to oxygenate the water. Its best to use a large container, such as a Brute trash can, and use an airstone to oxygenate the water vigorously. Water from wells or municipal locations, have very low oxygen levels and sometimes high CO2 levels. That's why some fish sink to the bottom after a water change. They have been shocked by the rapid decrease of oxygen in the new water. This behavior is usually not noticed after small water changes but common with large changes.

Another benefit of aging the water, is that it allows the chemistry of the water to stabilize. As the CO2 gasses off, the pH levels will typically rise. Fish don't care for rapid pH changes. They prefer that it stays stable.

I recommend adding a water heater while aging water. Set the heater to match the aquarium's temperature. This prevents the fish from being shocked by drastic temperature fluctuations.