It is time to learn about water changes! Water changes are necessary to help remove and dilute the pollutants that build up in your aquarium water. They also replenish some of the minor and trace elements that get depleted from the saltwater that are very crucial to coral health.


Newer reefers who perform regular water changes have dramatically higher long-term success rates than those who don't.


We have spoken to thousands of reefers over the years and this is one of those bits of advice that will drastically change your success rate in this hobby. Neglecting regular water changes through the first year WILL inhibit your success, it really cannot be more black and white.


Red Sea E170 with clean sand bed


We can take this a step further and tell you that hobbyists who keep a 1” or less sand bed and clean it with every water change will experience even higher success rates than those who don’t.


Success, in this case, meaning less algae growth and healthier inhabitants as well as a much higher likelihood of succeeding past the first 12 months into the 3 and 5 year range. After 2 to 3 years, the tank does become less dependent on water changes as a nutrient export method and there are advanced systems, methods or approaches to reduce reliance on them but this is something you grow into, it is not a starting point.


Water change


How To Perform A Water Change

We showed you how to mix saltwater in Episode #10 and will be using Tropic Marine Pro Reef for the tanks here. The idea of a water change is to improve the quality of the water which is all dependant on a quality salt mix.


A 10% weekly water change is the best schedule, for a 40 gallon tank that means removing 5 gallons of water into a bucket and replacing it with 5 gallons of clean saltwater. Alternatively, you can choose a 20% water change every other week which would require two 5 gallon buckets or 10 gallons total.


Python Gravel Cleaners and Siphons


Both strategies produce the same results. You can go larger than 20% but should then think about heating the new saltwater and matching parameters or at least ensuring they are close. For new reefers, it is best to stick with the 10% - 20% change so as not to accidentally shock the system with a dramatic change in water temperature or chemistry.


How to clean your sand bed with a siphon tube


How To Clean Your Sand Bed

While you are doing your water changes, your tank will greatly benefit from cleaning the sand at the same time. Use a Python 1” Pro Clean Gravel Wash or similar siphon tube to remove water from your aquarium into the buckets. Put the gravel wash into the sand and clean it. Sand will tumble around, removing detritus and water at the same time and leaving the sand behind. You can do small areas of the tank each week because you will likely fill the buckets before cleaning the entire sand bed effectively.


How to remove algae using a siphon tube


Tumbling can be controlled by kinking one end of the tube while you siphon with the other hand. At the same time if you spot a tuft of algae pinch it between the end of your siphon and your thumb to pull it off the rock and suck it out with the siphon.


For larger water changes, the Python No Spill System is a great option because it includes a valve that connects to your faucet that creates suction through the siphon tube. This makes it easy to pull water from the tank and drain it directly down the sink without any buckets.


Automatic Water Change Setup with Neptune Systems DOS


Likely not something you want to think about now, but water changes can be automated using something like the Neptune Systems Apex Aquarium Controller and DOS or the Auto Aqua AWC system. Just park this in the back of your mind for now because this is definitely an advanced approach but can really relieve you of the maintenance monotony when the time comes.


What’s Next

Now that you have the water change down and keeping your water clean, let’s take this to the next level and talk about polishing your tank water to be crystal clear using filter media, specifically Carbon.


5 Minute Saltwater Aquarium Guide Episode #23


Looking for a different topic or have questions? You can binge the entire 5 Minute Saltwater Aquarium Guide playlist right here on our website. We also invite you to join the #askBRStv Facebook Group which is a free resource for you to ask questions, get advice, interact with other hobbyists and get your daily reef aquarium fix.