How to Change the Water in Your Freshwater Aquarium the Easy Way
The Best Way to Change Aquarium Water
The weekly water change is the most important thing you can do to make sure the fish in your freshwater aquarium remain happy and healthy. Unfortunately, it’s also a step that some aquarium owners tend to overlook.
When life gets busy, fish-tank maintenance is often put on the back burner to be addressed later, or forgotten about altogether. Fish can die due to poor conditions, and you may end up feeling like this whole aquarium thing is more trouble than it’s worth.
This article will cover a quick, easy and painless way to keep your aquarium water clear and healthy without spending an hour or more cleaning every week, and without spilling water all over your carpet.
Remember that no aquarium out there requires zero maintenance but, with the right tools and planning, a lot of the hassle can be minimized.
It’s a good idea to perform a deep cleaning of your tank about once a month, or at least every other month. This means taking out all the decorations (if you don’t have live plants) and cleaning them, dealing with any algae issues, cleaning the filter and vacuuming the gravel. But these cleanings are very stressful for your fish.
A weekly water change doesn’t need to involve all of that, and can be relatively stress-free for both you and your fish. Keeping up with your fish tank maintenance schedule shouldn't be something you dread!
Changing the Water in a 10-Gallon Tank
If you have a small 10-gallon setup your weekly water change will literally take you minutes. You’ll need a small mini-siphon gravel vacuum and a bucket.
Please note: Any bucket you use for your fish-keeping hobby should be designated "fish only". Never use a household cleaning bucket for working with your fish tank as any residual chemicals will be harmful to your fish.
To change the water in a 10-gallon tank, simply use the gravel vac to siphon water from your tank into the bucket. Never remove all of the water; only take about 30%.
A good way to measure this, aside from eyeballing the tank, is to find yourself a 3-gallon bucket. When the bucket is full you know you’ve taken enough water. Discard the old water, fill the bucket with fresh water, pour it gently into your tank and your water change is done.
Water Changes in Big Tanks
For those with big tanks the job gets much more complex. If you want to, you can use a siphon and repeatedly fill and empty the bucket, then repeatedly refill your tank with the bucket.
This method may require a dozen or more trips back and forth between your tank and the water source. It’s time-consuming, back-breaking and messy, not to mention a real good excuse for taking up a different hobby. But there is a better way:
There are water-change systems on the market that drain the water straight from your tank to your sink. These systems involve a long tube that hooks up to your kitchen or bathroom faucet on one end, and has a gravel-vac fitting on the other end.
You can siphon water from the the tank and send it directly down your drain. When the tank is drained to the desired level, simply throw a lever and the tank begins to fill.
Sound easy? It’s definitely way better than carrying that sloshing bucket around. Here’s a look at how I use a water changer to do quick and easy weekly water changes.
Step 1: Set Up Your Water Changer
Water changers are designed to hook up to your kitchen faucet or similar water source. When in draining mode this hookup sends the dirty tank water right down your sink drain.
I use mine a little differently, though. Water changers come with tube lengths up to 50 feet, more than long enough to stretch to and out the door in most homes. I like to send my dirty tank water out onto my lawn instead of letting it go down the drain.
In the summer, I use it to water flowers and plants. This is just an effort at a little conservation on my part and certainly not necessary.
Whatever you choose to do with the old water, a water-change device makes it simple to siphon water from your tank and send it on its way.
Note: Throughout this article I'll be using the . This is the 50-foot model, which I prefer because of the way I drain the water (as explained above). However, there are shorter versions available if you don't need quite so much tubing. Aqueon Aquarium Water Changer
Step 2: Drain Water from the Tank
After you've set up your water changer as specified by the manufacturer all it takes is a flip of a level for water to begin to drain from your tank. Keep in mind that the purpose of the water changer is not only to siphon water, but also to clean the gravel.
We're not going to make use of the gravel-vac function for our super-easy water change, but you should use it when doing your monthly deep cleans.
Water changes should always be partial water changes. Again, we're only going to take around 30% of the old water out of the tank. You should never replace all of the water in your aquarium at once. While water changes are healthy for the fish, very extreme water changes can actually cause them a great deal of stress and possibly even kill them.
Remember, the reason you are changing the water in your tank is to dilute the natural waste made by the fish and uneaten food. In the wild this happens by the natural actions of the streams and rivers where the fish live. In your tank, you need to do it yourself with water changes. As the saying goes:
The solution to pollution is dilution.
Water changes do not take the place of regular tank cleaning and maintenance, but they do help a lot when it comes to controlling waste in the tank, and even preventing algae growth.
There is no need to remove the tank lid. You don't even need to turn your filter off as long as the intake is low enough in the water that it can continue to function.
You do want to make sure your heater is low enough in the tank that a significant portion of the heating element is not sticking out when the water is drained to its lowest point in the process.
Watch Out for the Little Fish!
It will take a few minutes for the water to drain out and you really can't do much but watch. Be aware that the tank-end of the tubing may pop out on its own, so you may want to wedge it between decorations so it stays put. If it seems secure, while the water is siphoning you can go and do something else for a few minutes.
However, if you have small fish in your tank you’ll want to keep a close eye on the open end of the tube that’s in the aquarium. Make sure they don’t swim up and into the tube where they can get stuck.
Yes, it can and does happen!
Healthy fish, even little ones, should be plenty strong enough to escape the pull of the siphon. The problem is, fish aren't very bright. The suction may cause little bits of debris to dance around inside the clear, plastic opening of the tube. Small fish may swim in chasing the debris and get stuck if you aren't careful.
Step 3: Refill the Aquarium
Refilling the tank with a water-change system is just as easy as emptying it. Make sure you have a strong connection between the tubing and the faucet receptor, otherwise water can burst everywhere.
You will want to close the lever on the tank-end of the tube before going over and flipping the “fill” lever at the faucet. When you return to the tank, flip the tank-end lever back to open and the water will start to flow.
Again, if you can secure the business-end of the tube in the tank you can leave it while you do something else. But don’t forget about it or you’ll end up with a flood! I use a timer with an alarm to remind myself, and, yes, I learned this the hard way.
Fill the tank just to the bottom of the filter outlet to allow water movement without too strong of a current.
Note: I get a lot questions asking why I didn't add dechlorinator or water conditioner at this step. That's because my water source is fresh, country well water water. It is somewhat hard, and thus naturally slightly high pH, but I've never used any additives or chemicals to adjust it. However, if you use a municipal water source or some other water supply that requires treatment you will need to treat your tank at this point.
One of the big questions when refilling a tank concerns the temperature of the water. Of course, tropical fish require temps in the mid-to-high 70s to be happy.
But since you are only changing around 30% of the water you can get away with adding cooler water to the tank; there is no need to try to match the water temp exactly.
I prefer to add cool water because of the way our water system heats water in our house. Cold water travels straight from the well to our tap, where hot water takes a lap through the water heater.
I prefer my fish get the purest water possible so I try to avoid as much heated water as I can. Note also, there is a big difference between cooler water and cold water. Never add ice-cold water to your tank. For some fish species, a temperature drop of as little as fifteen degrees can be deadly.
You might also notice that a burst of cooler water will invigorate some fish in your tank, and they may seem especially spunky after a water change. To them, a sudden influx of cool, fresh water simulates the start of the rainy season.
See the Aqueon Water Changer in Action
How Often Should You Change Aquarium Water?
Weekly water changes are a great idea, but they do not take the place of monthly or bimonthly deep-cleanings of your tank. You still need to vacuum the substrate and get all of that waste out of the gravel, clean the sides of the tank of any algae buildup, clean your decorations to keep them looking bright and perform regular maintenance on your filter system.
But these deep-cleanings can be stressful for the inhabitants of your aquarium, so regular water changes go a long way toward keeping your tank clean without freaking your fish out too often.
The water changer is a great tool for making water changes quick and easy. Once you have a little practice you can perform the maintenance described in this article in as little as twenty minutes, and you can spend much of that time working on other household tasks while your tank drains and fills.
No more carrying buckets around the house, and no more spilling water on your carpet!
Taking care of a tropical aquarium does take a little work, but it’s always better to work smarter than harder. Using the right tool for the job will mean you’ll have less dread for aquarium maintenance, and can enjoy your tank more.
Have fun, and here’s to many years of happy, healthy fish!
This article is accurate and true to the best of the author’s knowledge. It is not meant to substitute for diagnosis, prognosis, treatment, prescription, or formal and individualized advice from a veterinary medical professional. Animals exhibiting signs and symptoms of distress should be seen by a veterinarian immediately.