Cloudy water in fish tank

How to get rid of cloudy water in a new fish tank

Setting up a new fish tank can be intimidating, especially if you’re new to the hobby, and it can be concerning when things happen that you don’t expect. One of the first hurdles that beginner fishkeepers can expect to face in the early stages of setting up a new tank is cloudy water.

While cloudy water in a new fish tank doesn’t pose a significant threat to your tank inhabitants, and shouldn’t be a cause for concern, one thing it does do is obscure the hard-earned view of your beautiful fish, decorations and plants. Inconvenient and annoying, cloudy aquarium water interrupts the excitement of having a new tank, and if you take the wrong steps once it occurs it could stay longer than needed. In this blog, our fishkeeping experts will be taking you through what causes a new fish tank to go cloudy, what you should do to get rid of it, and how you can keep your water crystal clear.

Why is my fish tank cloudy?

The water in a fish tank can turn cloudy for a few different reasons, from regular overfeeding to introducing too many fish too quickly, but the most common cause in a new aquarium is a bacterial bloom. This occurs within the first few days of setting up a new tank and happens because of microscopic organisms feeding on the minerals and nutrients in the water. These microbes multiply quickly on their full diet and are visible in great numbers in the form of milky-coloured specs which turn the water cloudy.

The reason bacterial blooms are so common in new aquariums is because the setup is effectively a biological blank slate. There are no beneficial bacteria thriving in the aquarium filter yet, which, once developed, keeps the balance of water within healthy levels. Until this bacterial colony has grown, the free-floating milky bacteria is able to run rampant.

How to get rid of cloudy water in a new fish tank?

If you have a new aquarium and it's suffering from cloudy water caused by a bacterial bloom, the best thing you can do to fix it is to do nothing and wait it out. The microbes which colour the water milky will naturally die off on their own as soon as the food source (the nutrients and minerals in the water) has been exhausted. Without any interference from you, the beneficial bacteria establishing itself in your tank filter will inevitably win the tank territory war, and you’ll be left with clear water and a good bacteria colony.

You should also be careful not to make the problem any worse through any well-intentioned actions. The most common mistake people make when trying to fix cloudy water is to perform a partial water change. While this is an important part of a maintenance routine for an established tank, it should be avoided for a new system - especially if you have cloudy water. This is because any new water added to the tank will likely introduce more minerals and nutrients for the cloudy water bacteria to feed on, allowing them to feed and multiply even more, leaving you with a worse problem than you started with.

How long does a new fish tank stay cloudy?

If you do nothing at all, and are careful not to exacerbate the problem through water changes, your cloudy tank water should clear up on its own within one to two weeks. After this, your beneficial bacteria colony should be starting to establish itself well, and will contribute to the clear water in your tank.

How do you clear up a cloudy fish tank quickly?

While it's all well and good telling you not to do anything and wait for the cloudy water bacteria to die off over time, we know that beginner hobbyists may be tempted to try out ways of clearing the water so they can get to enjoying their new project faster. There are some methods which you can try which can do this, and we’ve run through these below:

  • Add live plants: Live aquarium plants compete for the minerals and nutrients in the water that the cloudy water bacteria eat, helping to starve them of their food supply faster. Plants are also great for your aquarium in the longer term too, helping you to build beneficial bacteria, limit algae growth, oxygenate the water and more. If you want to try out this method for clearing cloudy aquarium water faster, follow our handy beginner’s guide to aquarium plants. At Aquacadabra, we also sell a wide range of live aquarium plants which you can introduce into your new tank to help build a healthy ecosystem which is beautiful to look at. Browse the full range of live plants and planting supplies to get you started.
  • Seed the aquarium: As cloudy water in a fish tank is caused by free-floating bacteria running rampant, if you seed your aquarium with good bacteria you can establish a healthy ecosystem faster, which clears the water colour by killing off the microbes. The easiest way to seed an aquarium is to add some substrate from an established aquarium to your new tank by spreading a layer of it over your new gravel. This does, however, require access to an established tank, so if you don’t have any fishkeeper friends on which to rely on, you can also try seeding by using a biological starter product. An easy way to jump-start your new project, aquarium bacterial products like Interpet Fast Filter Start and Dr Tim’s One & Only work by introducing select cultures into your aquarium which help the cycling process.

Interpet Fast Filter Start 125ml, £6.70

Interpet Fast Filter Start 125ml

Dr Tims One & Only - Freshwater, from £37.95

Dr Tims One & Only - Freshwater

How to stop getting cloudy water in a fish tank?

While most fishkeepers will see cloudy water in their aquarium in the first few weeks of their new tank being set up, it’s possible to see this problem later down the line too. In an established aquarium, cloudy or discoloured water can be caused by anything from excess algae growth (which turns the water a sludgy green colour) to decomposing excess fish food or waste (which gives the water a yellowy tinge). If these issues do start to occur, you should follow our water testing guide to learn how to stay on top of your water quality responsibilities.

Keep your aquarium water clean and clear with Aquacadabra

Whether your new tank is currently suffering from cloudy water, or your patience has been rewarded and it's starting to clear, find everything you need to look after your fish tank at Aquacadabra. From full beginner’s guides to help you get started, to test kits and water quality supplies to keep your tank in top condition, we’re here to support you on your fishkeeping journey.