Do You Need to Do Water Changes for Planted Aquariums?

Freshwater planted aquariums, whether they’re strictly maintained for aquascaping or with a few fish to balance the ecosystem, will generally need less upkeep than tanks that lack plant species. Some aquascaping enthusiasts take pride in carefully balancing their ecosystems so they don’t have to worry about large water changes. This is one of the advantages of aquatic plants that fish keepers truly appreciate. They help with water oxygenation and complete with algae for nutrients. Nonetheless, even strict tanks will require water changes to keep the parameters in check.

The Need for Regular Water Changes

If the water in your aquarium looks clear, if there are no signs of algae, if the testing kit doesn’t show nitrate levels spiking over 10 ppm, and your pH doesn’t drop below 6.2, you’ll know things are fine and only a small 10 percent water change is needed. These water qualities are the result of the nitrogen cycle, which is invariably followed by the generation of nitrates and ammonia. Even an aquascape without fish or invertebrates will eventually generate a bioload of decomposed plant debris as well as toxins, hence the need for water changes.

The Use of Fertilizers

Along with proper lighting and a good substrate, the success of a planted tank will often be achieved through fertilizers and either CO2 gas or liquid “carbon source,” which acts like CO2, only much less expensive. Whether you use liquid fertilizers or the capsule kind that sit at the bottom of the tank, you’ll need to change between 20 and 40 percent of the water each week. Keep in mind that fertilizers release organic compounds into the water, and there will be a point when the Nitrobacter colonies won’t be able to control all the nitrates.

Recommended Water Change Frequency for Planted Tanks

Traditional aquascapes that don’t feature injected carbon dioxide and aren’t dosed with fertilizers won’t need as frequent water changes as long as there’s a very low fish bioload. We’re talking about lushly planted tanks that took a couple of months to establish and that are also home to a few fish. These low-tech tanks will only need 30 to 50 percent water changes twice a month rather than weekly. High-tech tanks with injected CO2 that receive fertilizing doses to support more exotic plant species will need weekly water changes of at least 25 percent.

The Water Change Process

Full conditioning and preparation of new aquarium water comes first. If you plan on dosing your plants with fertilizer, add it to the container of clean water. Estimate how much water will be changed by visualizing it on the aquarium’s walls. Drain the desired amount before doing any cleaning such as scraping or siphoning. This would also be a good time to take care of trimming. Always introduce clean and conditioned water slowly and gradually.

At Aquatic Warehouse, we carry everything you need to properly maintain a freshwater planted aquarium, and we’re also experts in providing the same for saltwater tanks and garden ponds. Come check out or store located in Kearny Mesa, order what you need from our website, or give us a call today at 858-467-9297 if you have any questions.