Water Changes and Routine Maintenance

The most important thing to remember when keeping any sort of aquarium is routine maintenance. Each type of aquarium requires specific levels of care, and this can be further increased or reduced dependent on your tank’s inhabitants. For all aquarists, however, routine maintenance means regular water changes, cleaning or replacing sponges and wiping the glass or acrylic down. Completing these three chores biweekly will ensure your aquarium is the aesthetic focalpoint you intended.


The Importance of Water Changes

Water changes are the most effective way to remove unwanted and potentially harmful substances from your tank. Purchase a test kit, such as API’s 5 in 1 Test Strips to regularly check the water for substances which would be harmful to your pets. The most common of these substances is Ammonia, which is a direct result of fish waste and uneaten food. Small and regular water changes are best when high ammonia occurs (5% per day for 1 week) to slowly reduce the amount present. This chemical is highly toxic to animals and plants (can cause burns) but also imperative to the nitrogen cycle. It must be removed but not too quickly. The second most common is Nitrate - the final product of the nitrogen cycle. High levels of this indicate that the cycle is complete and a water change is needed. Nitrate is not harmful to fish but plants and especially corals are sensitive to it. In a tropical or cold water tank 10% of the aquarium water should be replaced with fresh dechlorinated water every two weeks. In a marine set up 10% of the water should be replaced with fresh saltwater every two weeks.


Aside from removing excess levels of unwanted chemicals, water changes are important for refreshing quantities of trace elements creatures absorb through osmosis.


Topping Up

The water level in your tank will drop over time as some evaporates. In a tropical or cold water set up this should be replaced with dechlorinated water. In a marine set up this should be replaced with Reverse Osmosis (RO) water. RO water contains no trace elements at all so, preventing it from making unwanted changes to existing levels of trace elements. This is imperative for keeping corals. You do not want to top up saltwater as the salt does not evaporate and your tank will get exponentially saltier - to measure the salt content you will need a Refractometer. I use the D-D Refractometer as it is easy to use and accurate.

Drawing a small indicator line in a corner at the top of the water level (when the tank is full), and a second one a couple of centimeters lower will help you to gauge how much water has evaporated.


Cleaning Sponges and other Paraphernalia

Over time fish waste in your aquarium will build up. Every two weeks, whilst doing a water change, you should take out the sponges from the filter and wash them in the water removed from the tank. Be gentle when squeezing them out as large populations of ‘good bacteria’ (nitrosomonas and nitrobacter) can be lost during this process. Loss of these bacteria can cause deadly ammonia spikes in the water as the bacteria are no longer present to convert the ammonia to nitrite, then to nitrate. Replacing sponges can cause the same issue, so replace them one at a time and seed the new one by temporarily having both in the tank if you can.

The substrate in tropical and cold water tanks will need to be washed once a month. Gravel has gaps between the stones where decaying waste can lay unnoticed and unfiltered, if accidentally disturbed an ammonia spike can happen. Using a mechanical gravel cleaner such as the Python No Spill Clean and Fill Gravel Cleaner which drains as well as fills aquariums, and will not disturb fish or decor during routine maintenance”1. While I believe Python make the most practical gravel cleaner, there are others available from recognisable brands such as, Aquaone’s Vac-A-Tank  and Tetra’s GC30 Gravel Cleaner There are also electronic versions on the market such as Fluval’s ProVac which is suitable for fresh and saltwater aquariums.

Also once a month you should dismantle any filters, skimmers and wavemakers to wash away any detritus. Washing the impeller and surrounding area will keep it spinning freely - avoiding strain on the motor .


Cleaning the Glass or Acrylic

Something as simple as a fresh kitchen sponge can be used in a glass freshwater aquarium. A regular wipe down should prevent patches of algae that are hard to remove. However, stubborn algae can be removed with ease using an algae scraper, such as the TetraTec GS45 Glass Scraper Cleaner which has a hinged blade and a long handle allowing it to glide smoothly along the glass, and side protectors to stop it damaging the silicone. For deeper tanks, a ‘sponge on a stick’ is a must. The most effective, hassle free way to clean any glass tank, however, is a floating magnetic algae scraper like the Mag-Float Floating Magnet range of sizes to suit any size tank, is non-abrasive and floats for easy collection when finished.


If you have an acrylic tank then you will need a softer sponge or you will scratch the tank. There are many available. API’s Algae Pad is durable, inexpensive and works well. A plastic blade can be used to remove stubborn algae, and most algae magnets come with a plastic alternative.


Sticking to a rota will help you keep on top of routine maintenance and water changes (you will also need to incorporate your filter into this) You may have other equipment such as wave makers, protein skimmers, UV bulbs or other extra equipment, these may need specific maintenance to keep them working at their peak so be sure to read the manual. Below you will find the links to all the products I have mentioned above.


Thank you for reading