Best 5 Koi Pond Bottom Drains – Why Are They So Effective?

Apart from constructing a koi pond, keeping it clean is the key part of owning it.

As the name suggests, aerated bottom drains provide extra aeration in the pond and can be very useful if a quality air pump accompanies it.

However, this calls for an additional cost. On the other hand, non-aerated bottom drains do not have this feature.

Bottom drains are available in two types which include;

  • Non-aerated bottom drains
  • Aerated Bottom drains

Both types are perfect for removing dirt that has settled at the bottom of the pond pumps.

There is a wide variety of bottom drains in the market, and generally, it is a good thing.

However, it can easily cause a fix in making the best buying decision. That is why we have compiled a guide to ensure that choosing the best bottom drains for your koi food pond isn’t so confusing.

  • Dreampond Koi Toilet II Bottom Drain 4 w Dome

    Dream Pond Koi Toilet II Bottom Drain

  • AQUADYNE Rhino Retro 2 Bottom Drain

    Aquadyne Rhino Retro Bottom Drain

  • Best Aerated Koi Pond Bottom Drains

    Best Aerated Koi Pond Bottom Drains

  • EasyPro 4 Heavy Duty Bottom Drain with Air Diffuser

    Easy Pro-4″ Heavy-duty Bottom Drain With Air Diffuser

  • DreamPond Retrofit Bottom Drain 3 w Air Diffuser

    Dream Pond Retrofit Bottom Drain 3″ With Air Diffuser

  • Best Non-aerated Bottom Drains

    Best Buy

    Dream Pond Koi Toilet II Bottom Drain

    Dreampond Koi Toilet II Bottom Drain 4 w Dome

    This is a non-aerated user-friendly bottom drain system, mostly recommended for small, sparsely populated ponds.

    It is generally small, but this does not compromise its ability to eliminate fish smack and waste that settles at the bottom of the pond.

    Dream Pond Koi Toilet II Bottom Drain allows you to achieve a perfectly clean lake at a pocket-friendly price.

    What We Liked About Dream Pond Koi Toilet Ii Bottom Drain

    Dream Pond Koi Toilet II Bottom Drain is relatively small, effortlessly offering ample space for your koi fish.

    Moreover, you do not have to worry about maintenance and replacements as it is made of molded ABS, guaranteeing quality and durability.

    Product Overview

    This is a lightweight (2.8 pounds) yet massive-duty pond bottom drain.

    It is fitted with a 4-inch outlet connection where you can fit four-inch internal diameter pipework, which is best for waste removal in a gravity-based system.

    Since the outlet is at the bottom of the system, a 90′ elbow fitting is required to connect the bottom drain to your drainage pipe.

    This unit has a dome-shaped top, ensuring a smooth flow of water quality. Additionally, its attachments are fitted with a thick flange and liner ring for a perfect grip on the liner.


    • Easy to handle and install
    • Cheap
    • One year warranty
    • Made of molded ABS for quality and durability


    • Unsuitable for deep and densely populated


    Unless your fish pond is deep and with a dense fish population, installing sophisticated bottom drain systems that are mostly fitted with air diffusers is unnecessary and cost-ineffective.

    Dream Pond Koi Toilet II Bottom drain is cost-friendly, easy to install, and perfect where the removal of solid waste is the primary concern. It is the ultimate solution for small ponds.

    Aquadyne Rhino Retro Bottom Drain

    AQUADYNE Rhino Retro 2 Bottom Drain

    Aquadyne Enterprises presents a unique bottom drain, carefully manufactured with keen attention to detail to achieve a simple yet very durable product.

    Unlike most bottom drains where speed welding is used, Aquadyne Rhino Retro Bottom Drain joints are hand-welded, resulting in units of unmatched strength.

    What We Liked About Aquadyne Rhino Retro Bottom Drain

    The best thing about these bottom drains is that injection-molded parts are of no use. This function is a guarantee of quality and longevity.

    Additionally, unlike most products where speed welding is used, all joints are hand-welded in the Aquadyne rhino retro bottom drain.

    You can also install the unit in already existing ponds by placing it on your pond’s liner. Its smooth finish ensures that the coating is not damaged.

    Product Overview

    Aquadyne Rhino Retro Bottom Drain is a durable unit made from heavy-duty PVC material.

    You can easily install this bottom drain to existing or pre-construct ponds without underground plumbing.

    You can do it by merely filling the base of the bottom drain with sand to prevent floating and only connecting it to the pump suction line.

    Ensure you place it in the deepest bottom or at the pond’s center to facilitate effective cleaning.

    It is available in the market, either 2 or 3 inches to suit your needs. Attachments in this unit have a thick flange and a liner ring for a perfect fit eliminating the risk of cracking.

    They are also machine-fitted; therefore, they don’t require gap filling. It is important to note that an improved version of the Aquadyne Rhino Retro Bottom Drain comes with an air diffuser.


    • Can easily be installed in an already existing pond
    • Made from heavy PVC material ensuring durability
    • No injection-molded parts, therefore, guaranteeing quality
    • Smooth finishing


    • Ineffective if it is wrongly placed.
    • No pond aeration


    Repairing and replacing broken bottom drains can be quite expensive.

    Aquadyne Rhino Retro Bottom Drain is a quality product with a lifetime assurance of a clean pond without paying extra repairs.

    Additionally, its portability specification enables you to move it to the shallow part of the pond in cold seasons, leaving a conducive warm environment at the bottom of the bond for your koi fish.

    Best Aerated Koi Pond Bottom Drains

    Best Aerated Koi Pond Bottom Drains

    Koi Toilet I Aerated Bottom Drain

    Koi fish can grow to an immense size, consequently producing a lot of waste, and therefore having an efficient and effective bottom drain system is paramount.

    Koi Toilet I Aerated Bottom Drain can be termed a superior model of Dream Pond Koi Toilet II Bottom Drain.

    It measures 16.5 by 16.3 by 14.4 inches with a weight of 10.55 pounds. This bottom drain unit features unique features, and its ability to aerate and get rid of smack in your koi pond is just incredible.

    What We Liked About Dream Pond Koi Toilet I Bottom Drain

    Most bottom drains are difficult to maintain. However, Dream Pond Koi Toilet II Bottom Drain is a threaded center column that offers easy access during maintenance.

    It also has well-secured screws. Just like Dream Pond Koi Toilet II Bottom Drain, its attachments are fitted with a thick flange and liner ring for a perfect fit around the pond liner.

    This bottom drain also comes with an effective air diffuser that cannot disappoint.

    Product Overview

    Dream Pond Koi Toilet II Bottom Drain is fitted with a 4-inch outlet that allows you to connect 4-inch internal diameter pipework to obtain optimum efficiency in waste removal.

    However, adapters can be used to reduce the outlet to the inches, but we wouldn’t recommend that as you will not be able to utilize the bottom drain to the maximum.

    This unit is also fitted with a one-inch air inlet, which allows large air intake providing a very well-aerated environment for your fish.

    It also reduces the possibility of back pressure on the air compressor. We also noticed the internal check valve makes it impossible for debris to enter the air compressor. Lastly, it is made of molded ABS to ensure longevity.


    • Made of molded ABS for quality and durability
    • High aeration capability due to the larger air intake
    • No backpressure due to the large air inlet
    • It is equipped with an internal check valve
    • One year warranty


    • It is a bit expensive in comparison to other similar designs


    Regardless of its price, which could be termed steep in contrast to other aerated bottom drains, Dream Pond Koi Toilet II still stands out as one of the best products.

    It offers matchless performance offering the best possible environment for your koi fish.

    Easy Pro-4″ Heavy-duty Bottom Drain With Air Diffuser

    EasyPro 4 Heavy Duty Bottom Drain with Air Diffuser

    They say cheap is expensive in markets, but this is not the case with the Easy Pro-4″ Heavy-duty bottom drain with air diffuser.

    It features a great combination of superior features yet offers the best price-to-value ratio.

    Easy Pro-4″ Heavy-duty bottom drain with air diffuser is one of the best base drains in the market, and just as the name suggests, it is a hardy product making it perfect for koi fish ponds.

    What We Liked About Easy Pro-4″ Heavy-duty Bottom Drain With Air Diffuser

    This bottom drain offers your koi fish an environment free of dirt and with an ample supply of oxygen.

    It has a high-quality air diffuser fitted with an appropriate air pump that can aerate up to 10000 gallons of water.

    Despite the high-quality features and unbeatable working capability, the Easy Pro-4″ Heavy-duty bottom drain still offers a pocket-friendly price for an aerated drainage model.

    Product Overview

    This 12.65 pounds aerated bottom drain is manufactured with expertise using the rotational modeling process offering superior strength.

    It is fitted with a 4-inch outlet connection, which is standard and most suitable for draining solid waste through gravity.

    A reducing male adopter can be used to connect the pump inlet to a 3-inch pipe if need be. It has a half-inch air inlet, which is threaded, and therefore there is no need for rubber-threaded coupling.


    • Pocket-friendly compared to other aerated models
    • Has high aeration potential
    • High capability to remove solid waste, making it suitable for koi fish ponds
    • Has a one-year warranty
    • Highly durable due to the use of the rotational modeling process


    • Backpressure may occur due to tiny air inlet


    Easy Pro-4″ Heavy-duty bottom drain with air diffuser is highly rewarding. Due to its high aeration capacity, you can use it in large and highly populated koi fish ponds.

    Its sturdy design ensures that you use it for an extended period. It is a bottom drain that will give you value for your money.

    Dream Pond Retrofit Bottom Drain 3″ With Air Diffuser

    DreamPond Retrofit Bottom Drain 3 w Air Diffuser

    Having a koi pond without a bottom drain can be quite a headache as it requires constant draining of the pond and cleaning.

    Despite having a wide variety of base drains in the market, it is tough for you to install them in an already existing or pre-constructed pond.

    Dream Pond Retrofit Bottom Drain with Air Diffuser relieves you from what seems like an insolvable problem as it works perfectly by just placing it at the lowest point in the bottom of your pond.

    What We Liked About Dream Pond Retrofit Bottom Drain3″ With Air Diffuser

    The most eye-catching feature of this bottom drain is that you can easily install it to an already existing pond without having to cut your liner.

    This eliminates the possibility of a leaking pond, which mainly emanates from poorly installed bottom drains.

    Product Overview

    This is a 12 by 12 by 4 inches 3 pounds bottom drain unit that has been mainly developed for installation in already existing or pre-construct ponds.

    Setting it up is secure, and all you have to do is place it at the lowest bottom of the pond to ensure the effective removal of all solid waste.

    It is essential to fill the base with sand or gravel to anchor the unit at the Bottom of the Pond firmly. It is fitted with 3-inch outlets, which is very efficient if utilized to the fullest.

    At the top of this unit is an air diffuser, which ensures optimum circulation and aeration in the pond.


    • Easy to install
    • Facilitates easy upgrading of already existing ponds
    • Eliminates the risk of leaking pond that results from poor Bottom drain installation
    • Fitted with an air diffuser
    • Superior sweep designs that ensure the flow of water


    • The wrong placement could easily compromise its ability to remove debris


    Sanitary ponds are difficult to achieve, especially with koi fish, as they produce a lot of waste. This gets even tougher if your pond is not installed with a bottom drain.

    Dream Pond Retrofit Bottom Drain 3″ with Air Diffuser is the go-to option as its unique features ensure easy and risk-free installation in already existing ponds.

    Our most frequently asked questions on koi pond bottom drains.

    Is It Compulsory To Have A Bottom Drain In A Koi Pond?

    Yes. Maintaining a clean pond is essential for the successful raring of koi fish. This can only be achieved by continually filtering out solid waste from the pond.

    Solid dirt settles on the pond floor, and without a bottom drain, filters cannot remove it. Pond bottom drains simply push dirty pond water to the filter and push it back into the pond once it is clean.

    An alternative to installing bottom drains is to remove the fish from the pond, drain it, wash the pond, put clean water, and then place the fish back in the pond.

    This is practically unmanageable, considering it must be done frequently to achieve a fresh pond. Bottom drains offer a 24/7 cleaning mechanism without having to lift a finger.

    Additionally, bottom drains with air diffusers keep the pond oxygenated adequately.

    Is It Possible To Install a Bottom Drain In An Already Existing Pond?

    Yes, it is possible. In fact, with the current developments in the raring fish industry, it is effortless.

    There are two alternatives to equipping your existing pond with a bottom drain.

    One, you can choose to go for the drains installed under the pond’s liner. This means a lot of underground plumbing and a very high risk of leaking ponds.

    Secondly, and this is what we would recommend, some drains are simply lowered in the pond and placed on the floor of the pond. They work similarly to those installed under the pond as long as they are correctly set.

    Is It That My Koi Pond Bottom Drain Has An Air Diffuser?

    No. The essence of an air diffuser is increasing oxygen supply and aerating the pond.

    This is only necessary if you have a huge pond with a dense fish population.

    As mentioned earlier in this discussion, small ponds work fine without an air diffuser, and installing one would unnecessarily cost extra.

    It is, however, important to carefully assess whether your pond requires it or not.

    How Many Bottom Drains Are Required For My Koi Pond?

    This is primarily dependent on the size of your pond. Extensive ponds may require more than one.

    However, the layout of the plumb work should also be considered. A general estimation states that one bottom drain can clean 5000 to 6000 gallons of water effectively.

    We recommend a bottom drain fitted with a 4inch outlet. You can install four-inch ID pipework, the most useful size for waste removal.

    Other factors that determine the number of bottom drains required include the shape of the pond and your preference.

    Factors To Consider Before Going For Your Pond Bottom Drain


    Bottom Drains can either be installed during the construction of a pond or to an already existing or a pre-construct pond.

    Installing it during the initial construction is more comfortable as the pond will be designed to adequately accommodate the bottom drain as well as the piping work that comes with it.

    However, there are so many restrictions when it comes to an existing pond. You have to remove the liner of or pond and do so much excavation to install a bottom drain. This is quite expensive.

    Hence, with existing ponds, it is advisable to go for bottom drains that are simply placed on the liner without cutting through them.

    Such a decision may help prevent leaking and save you a lot of money.


    Other factors such as quality, durability, ease of installation, etc., can be considered to carry more weight than price.

    Even so, you cannot buy what you cannot afford. It is imperative to choose a bottom drain that is within your budget.

    However, this does not mean you have to get a less effective unit for your pond.

    There is a wide variety in the market, and just with the proper guidance, you can get an affordable bottom drain that perfectly caters to your pond’s needs.

    Quality And Durability

    Replacing malfunctioning bottom drains now and then can be expensive. Frequent damages occur due to poor quality of Bottom drains.

    Durability and quality are mainly dependent on the process and materials used in manufacturing.

    For instance, units made by hand welding are sturdier than those made by speed welding.

    Some manufacturers also prioritize profits over quality and therefore use injection molding, which results in cheap bottom drain parts that are prone to breaking.

    It’s, therefore, vital to get adequate information before making a purchase.

    Aerated Verses Not –aerated

    The decision to buy either an aerated or a non-aerated bottom drain depends on the size of your pond.

    It may also depend on your koi stock. Even if you have a separate aerator already in place, buying the aerated bottom drain models is unnecessary.

    Both the investment and maintenance cost of aerated models is high in comparison to non-aerated models, and therefore it is advisable only to buy them where aeration is necessary.

    Final Verdict

    Koi fish carries a very high aesthetic merit. The good news is that it is quite easy to have a pond in your yard with koi pond bottom drains.

    However, you must get the right model to avoid unnecessary costs and stress. This article provides you with all you need to buy a bottom drain for your koi pond.

    With the above insights from experts, making the right purchase decision is a cinch.

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