Saturday, May 18, 2024

How often you need to Change Water in your Fish Farm

How often you need to change water for the fishes on your fish farm largely depends on your management system which includes your stocking density, the type of water you are using and the type of feed you are giving to your fishes.

High stocking density will get the water dirty earlier because the more they are, the more the quantity of feeds and feed wastes and also the more the wastes from them so high stocking density will necessitate regular change of water for the fishes.

In addition, contaminated source of water and local feeds get water dirty easily and so will call for regular change of water. Generally, water in a fish pond should be changed at least once in two weeks and also as soon as the oxygen level of the water is low. Therefore careful monitoring should always be carried to ensure that the water oxygen level is maintained in its good quality as nothing kills the fishes faster than bad water.

Ensure to change your water immediately you discover any abnormal signs from your fishes; do not wait for later as every minute counts in fish farming business. Your “LATER” may end up becoming your “LOSS” if proper care is not taken. Therefore protect your investment.

Meanwhile, changing your pond water is not just something you do for the sake of it. Changing water in ponds, just like in aquariums, is essential to the health and survival of the fish and the greater ecosystem.

Simply put, substances like ammonia, nitrates, nitrites, colors, odors, and other toxins will build up in the water over time, which is also true for uneaten food, fish waste, and other organic materials. These are all things which will put the health of your fish and the whole ecosystem in jeopardy.

Preforming weekly water changes in your fish farm among the dirty waters in any pond is a fast and easy way to remove a good chunk of these substances from the water at once. It will add some fresh water to the mix and help take some of the load off of your filtration unit too.

This is not something that you can or cannot do depending on whether you have time this week. Changing the water in your fish farm ponds is absolutely essential if you want to see the inhabitants live a long, healthy, and happy life.

Read Also: How to determine if the Oxygen Level of the water in your Fish Pond is enough

Changing Pond Water in a Fish Farm – The Amount

Now, how often you change your pond water does depend on the size of the pond itself. When it comes to smaller ponds, which here are classified as being under 5,000 gallons, you will want to change the water every single week, changing roughly 15% of the water each time. Larger ponds over 5,000 gallons in size require a weekly water change of 10%.

Now, if you have a super heavy bio-load in the tank, or in other words, lots of fish, you definitely want to stick to these numbers, but if you have a light bio-load, for smaller ponds, a 10% weekly change should do, and for larger ponds, a 5% weekly change should be adequate. Either way, performing weekly water changes is essential.

How To Change Pond Water in a Fish Farm

There are a few different methods of changing pond water, so let’s go over each of them, as one might work better for you than another. Keep in mind that the first method mentioned here is the least recommended one, but for smaller ponds it does work alright.

Method 1: For Smaller Fish Farm Pond

You can use a pump or siphon to drain the desired amount of water out of the pond. You can then use a hose to refill the pond to the ideal level. What you need to keep in mind here is that public water is usually full of chlorine and chloramines, which absolutely need to be removed from the water. This means that you need to use water conditioner and treatment options in order to remove the chlorine and other contaminants.

Please folks, if you choose to do it this way, the water conditioner absolutely needs to be added to the pond before you add new water, not after. If you do it this way, you also run the risk of flooding the pond if you happen to forget the hose in there for too long. This method is not recommended.

Method 2

One of the easiest methods to use still involves a pump or siphon, but you will be treating the new water before it enters the pond. Either way, drain the desired amount of water out of the pond with a siphon pump.

The difference between this method and the first one we went over is that here you will be preparing the water first, which in all reality is easier and safer for the fish.

Measure how much water you will need to add back into the pond and put it in some kind of pool or container, or whatever else you have that can hold the necessary amount of water. Letting it stand will help chlorine and other chemicals dissipate, plus you have a safe place to add water conditioners and treatment options.

After the water has stood for about 12 to 24 hours, you can then slowly pour it back into the pond. Remember guys, do not drain out the old water before the new water is ready to go.

Method 3

The third method tends to be the easiest for the long term, but it does take time to set up, plus is costly too. First off, you will need an overflow drain, which is a device that allows water to escape the pond when it reaches past a certain level.

You will then need a permanent water line installed that always has new water coming into the tank. You will need some kind of drip mechanism or trickle filter in order to slow down the water flow.

The aim here is to change from 5 to 15% of the water per week, but you are doing so constantly, with a teeny bit of new water always coming in and a little bit always going out. Like we said, this method is best for larger ponds as it will cost a good deal of money and take a lot of work to set this water changing method up.

However, once it is set up, you will never really have to do much work again in terms of water changes.

Read Also: How to determine if your Housing is Conducive for your Fishes

How To Clear Up Fish Farm Green Pond Water

If you have green pond water in your fish farm, it means that you have a type of algae blooming in there, plus some other substances too. Let’s talk about how to clear up that green pond water right now.

Green pond water is almost always caused by a certain type of algae blooming in the water. There are various ways to help get rid of algae and cut back on that green tinge.

Increase Filtration

One of the best ways to clear up green algae pond water is by increasing filtration. First of all, you should already have a good 3 stage filter in place, on that engages in all 3 major types of filtration, these being mechanical, biological, and chemical filtration. Mechanical filtration removes waste that can discolor the water, plus it removes waste than breaks down and releases substances into the water.

Biological filtration clears the substances out of the water, like ammonia and nitrates, which are created when waste and organic matter breaks down. Chemical filtration removes other toxins, colors, and odors from the water. This is important because algae feeds on things like ammonia.

Therefore, a good filtration system will help cut down on green water. If your filtration system is not powerful enough, you might need to perform an upgrade, get a new one, or just get a second one. Also, be sure to maintain your filtration system and clean it regularly.

Decrease Sunlight

Placing your pond in an area that is not too sunny, at least not all day long, will also help cut down on green water. Algae, just like other plants, needs sunlight to perform photosynthesis. Without as much sunlight, algae will not be able to bloom and therefore your green water problem should clear up.

Algae Eaters

There are animals you can add to your pond which will eat the algae as soon as it blooms. Koi fish, goldfish, frogs, and snails will all eat algae.

Dye The Water

Yes, we are talking about clearing up green pond water, but we are talking about green water caused by algae. You can in fact dye your pond green, blue, or even purple in color, at least partially (more on Pond Dyes over at this article).

This will help stop sunlight from penetrating too far into the pond, thus taking away one of the food sources which algae needs to bloom.

Add More Plants

The final thing that you can do to help clear up green pond water is to add more plants to the mix. First off, submerged plants will filter out things like ammonia and nitrates out of the water, thus removing the fuel that causes green algae blooms.

Second, you can add some floating surface plants into the pond, as this will help block some sunlight from getting through to the water, thus also removing a food source from the algae.


Folks, the bottom line is that for your fish farm business to become successful, changing pond water on a weekly basis is essential for the health of the community. Yes, it does take some time and effort to do each week, but it is absolutely crucial, and there are some methods that are easier than others. If you have green pond water, follow the above tips to remove it.

Related: Anatomy of Fishes: Female Fish and their Reproductive Strategies


Benadine Nonye is an agricultural consultant and a writer with over 12 years of professional experience in the agriculture industry. - National Diploma in Agricultural Technology - Bachelor's Degree in Agricultural Science - Master's Degree in Science Education - PhD Student in Agricultural Economics and Environmental Policy... Visit My Websites On: 1. - Your Comprehensive Practical Agricultural Knowledge and Farmer’s Guide Website! 2. - For Effective Environmental Management through Proper Waste Management and Recycling Practices! Join Me On: Twitter: @benadinenonye - Instagram: benadinenonye - LinkedIn: benadinenonye - YouTube: Agric4Profits TV and WealthInWastes TV - Pinterest: BenadineNonye4u - Facebook: BenadineNonye

5 thoughts on “How often you need to Change Water in your Fish Farm


    Very educative piece. I have learnt a lot and thank you madam. I have just started my catfish farming and hope to do well.

    • Agric4Profits

      Thank you so much and we are glad that you find our article very helpful!
      Nice to hear that you have started your catfish farming business and I wish you good luck

  • Austin

    Wow! This is article is very informative, thanks a lot!
    I’m about to go into Catfish farming and I’ll need all the help I can get.

  • Polycarp Babajada

    really I have leaning a lot God blessed this company

    • Benadine Nonye

      Amen… thank you so much and I’m glad you find the article useful!


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