How Often Should You Water Change Your Planted Tank?

Planted aquariums

 

 

 

Heavily planted aquariums look great and are becoming increasingly popular in the fishkeeping hobby. Aquascapes provide a natural eye pleasing environment for your fish. Plants have many benefits for fishkeeping, they compete with algae and benefit the water quality by absorbing harmful nitrate. You might hear people mention different water change frequencies even though they all have planted tanks, so how often should you be doing water changes? This is what I am going to cover in the article.

 

Why do we do water changes

 

 

When keeping fish, we do water changes to keep the water quality in good shape for our fish but what does that mean? So, to start with we need to talk about the nitrogen cycle, something that all aquarium hobbyists should be familiar with. If not, be sure to research this concept as it’s crucial to setting up a fish tank and keeping your fish healthy in the long run. In a cycled tank when fish create toxic ammonia beneficial bacteria convert ammonia into nitrite, then another type of bacteria convert this nitrite into the much less harmful nitrate. Although nitrate is not completely harmless it is far less of a problem than ammonia and nitrite, especially at low levels. However, over time nitrate can build up in an aquarium to high levels, which can cause problems for your fish and lead to a shortened lifespan. The solution? Regular water changes, by changing say 50% of the water you will have cut the nitrate in half by diluting it with freshwater. In a planted tank some if not all nitrate gets used up by plants, creating a healthier environment for your fish. Read on to find out why water changes can still be important for planted tanks.

 

Not all planted tanks are the same, some aquariums are heavily planted tanks with 90% of the substrate covered in fast growing plants whereas some hobbyists may choose to go for a more sparsely planted setup with just a few epiphyte plants such as Anubias or Microsorum. In general, heavily planted tanks will require less water changes to keep nitrate levels down as it is being absorbed by the plants. Some heavily planted aquariums become completely depleted of nitrate due to lots of healthy plant growth, in these situations adding fertilisers is the best route to go down, however this is another topic all together. In a lightly planted tank, you may find nitrate continues to rise over time, not as fast as if there were no plants but you may still need to do weekly water changes to keep nitrate in check. For your fish you want to aim to roughly keep nitrate below 20ppm for long term success. In the wild nitrate rarely builds up as most of the freshwater fish we keep originate from rivers and lakes in nature. Rivers have fast flowing water meaning nitrate is washed away and replaced with new water constantly, rivers and lakes also have massive water volumes meaning nitrate will always be diluted down.

 

Water changes can help your plants

 

Plants use NPK (Nitrate, Potassium and Phosphorous) to grow, these are called macro nutrients. However this is not all they use, these also need micro nutrients (Iron, manganese, copper ..etc) which are in various quantities in your tap water depending on your supply. You may have witnessed plant deficiencies some points, pale growth, stunted growth and yellow leaves are all sign of a nutrient deficiency. So, it is very important to always keep these nutrients available for your plants to ensure healthy growth. You might be tempted to skip water changes as your nitrate is low due to your heavily planted tank, and everything is looking great, but this may not last. Over time, deficiencies may develop in your plants due to a lack of macro or micro nutrients. For lightly planted tanks regular water changes with freshwater containing most of the needed nutrients may be enough but for heavily planted tanks a combination of regular large water changes and liquid fertilisers will be needed to keep you plants heavily.

 

Everything in balance

 

As most experienced hobbyists know your planted aquarium will eventually reach a balance and by regularly testing your water you will develop a routine to keep things running smoothly. The first few months are usually a learning curve in understanding how much your plants are consuming and what maintenance schedule works. Just keep an eye out for small changes in new growth of your plants to ensure they have all the nutrients they need. Now aquarium balance is important but so is balance for you the fish keeper. After all, I’m sure you originally started this hobby for its peaceful relaxing influence and now you’re starting to worry about your plants as well as your fish which can be daunting to newcomers. Give it a go I say! Mainly focus on water parameter from a fish perspective but why not try some hardy plants.  Adding a few slow growing hardy plants can be a great place to start keeping planted aquariums. But if you are up for the challenge, give a heavily planted tank a go! Just be mindful you may struggle with certain species of aquatic plant at first, but this is all part of the learning process. Do your research and be realistic. There is no point planning a high tech fast growing aquascape which needs 3 water changes a week if you have a busy schedule, a low tech easy planted tank may well suite you better. Keep in mind some plant species only thrive with the addition of CO2 and very high lighting so be sure to research the plant species you plan to keep. Care for your fish and have fun!

 

AQUAnatur – UK Aquascape Aquarium Specialists

 

Aquanatur stock a variety of plants and aquascaping products. If you have any questions, please contact us or leave a comment, our expert team are always happy to help!

 

By Alasdair McPhail