How To Dechlorinate Tap Water For Ponds

Regular pond maintenance is key to having a healthy pond for your fish to flourish and dechlorination is a vital aspect to maintaining your ponds eco-system. There are several ways to dechlorinate tap water for your pond with some being better than others and them all having there own distinct advantages and disadvantages.

In this guide we will be explaining everything you need to know about pond water dechlorinators and how to safely remove chlorine from your tap water. We will be going through the various ways and pointing out the pros and cons of each method with the aim of helping you decide which is the best for your needs.

But first!

Why Should You Dechlorinate Your Tap Water

As most people already know the water companies have been adding Chlorine to our drinking water for a very long time to make it safe for us to drink. In more recent times the addition of Chloramine has been introduced to tap water as well. Chloramine is very similar to Chlorine but has less odour and taste.

Both of these water treating chemicals are excellent at killing germs and harmful bacteria but are harmful to most forms of aquatic life including Koi and goldfish.

As all pondkeepers know it is of the utmost importance to ensure that Chlorine and any other impurities are removed before introducing tap water to a pond. Water that is free from Chlorine helps with the growth of beneficial bacteria as well as being the optimum environment for healthy fish. Chlorine can cause many adverse health problems for your fish if not removed.

Different Ways To Remove Chlorine From Tap Water

Natural Way – Leave To Stand For 24 Hours

naturally remove chlorine from waterIf you have a small garden pond that is in need of a top up then you can simply leave your tap water in a bucket for between 24 and 48 hours. This will allow the Chlorine to dissipate in to the atmosphere naturally. The great thing about this method is that it is totally free. On the flipside it is not an immediate solution and isn’t ideal for larger ponds.

A great way to speed up this process is to use a fountain pump. A fountain pump dramatically increases water circulation and the amount of water that comes to the surface and in to contact with the air. This aids with the dissipation of Chlorine and other chemicals.

If you live in a hard water area then the levels of Chloramine in your tap water will be considerably higher and should be taken in to consideration. Unfortunately Chloramine doesn’t disperse in to the atmosphere and has to be removed using one of the following methods.


  • Doesn’t cost a penny


    • Only suitable for small ponds
    • Takes a while

Water Conditioner/Chemical Treatment

chemical water dechlorinator This method is the one most people are probably familiar with and the most popular way to treat tap water for ponds. Using a water conditioner offers great versatility as they can be used to treat water both before you add it to your pond and/or to the actual pond water itself, fish included.

Water conditioners are suitable for both small and large ponds and are ideal for new ponds. The best brands on the market remove Chlorine, Chloramine, Ammonia and heavy metals from tap water.

To use a water conditioner you simply refer to the instructions on the back of the bottle. In some cases a single 1 litre bottle can treat up to 20,000 litres of water.


      • Works instantly
      • Affordable for small to medium sized ponds


      • Can be expensive for big ponds
      • Means adding chemicals to your pond

If you decide to go with a water diminisher we recommend Envi Chlorine Clear or Blagdon.


Chlorine Klear uses Vitamin C to instantly remove all harmful chlorines and chloramines from water. Using Vitamin C is the most natural, and beneficial way, to remove chlorine from your tap water. It effectively neutralises chlorine and is safer to use than a sulfur based dechlorinator.

Carbon Filter Hose Attachments

One of the most convenient ways of keeping your pond in top condition is with a carbon filter hose attachment. These handy little devices are simply fitted to your hosepipe with standard hose attachments. They contain a carbon filter with activated charcoal which effectively neutralizes chlorine, chloramine, bromine among many others. This is done before your tap water reaches your pond and is a great benefit to using this method.

 Carbon Filter Hose dechlorinator

The initial outlay of this method is more expensive than usng a water diminisher but works out cheaper in the long run. The Evolution Aqua Dechlorinator 12″ Carbon In Line Filter 12″ is a good affordable and high-quality option that can treat 150,000 Litres with a max flow rate of 9 lpm. This method is best for medium to large ponds.

3 Stage Water Filtration Systems

If you have a large pond stocked with plenty of fish then you may want to think about investing in a water filtration system. These are perpect for Koi and provide the optimum environment for them to flourish. Similar to carbon hose attachments they use activated carbon to purify the water and remove any contaminants that could be harmful to your ponds residents.

Water filtration systems work in three stages for maximum effect.

      • Stage 1 – 5 micron particle filter (PP) – removes/reduces sand, dirt, iron and other particles
      • Stage 2 – Granular Activated Carbon filter (GAC) – removes/reduces chlorine and dissolved organic contaminants
      • Stages 3 – Block Carbon filter (CTO) – further removes contaminants from water

3 stage water filtration system

Using  a water filtration systems isn’t best suited for every pond and we wouldn’t recommend them for small ponds either. However, if you have a big pond they are a good way of maintaining a healthy pond. In terms of setup time they require a bit more work than a hose attachment but once done you are good  to go for a long time.


      • Saves both time and money
      • You don’t have to add chemicals to your pond


      • Setup can be tricky for some

Final Words

With as many ways as there is to dechlorinate your tap water there should be a method that is suitable for everyone on our list. The key to finding the best option is to weigh up the pros and cons of each one. If you have a small pond then a water diminisher should be sufficient for your needs. Those with a large garden pond may find a carbon hose filter or a 3-stage dechlorinator the best way to go. Either way pond maintenance is something that should be kept on top of throughout the year to ensure your fish pond or wildlife pond remains healthy.

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