Tadpoles and Pond Pumps Don’t Mix. What Can You Do?

A garden pond is a great way to attract all kinds of wildlife to your garden. Adding a feature such as a waterfall or fountain brings the pleasant sound of running water to your garden which in turn attracts still more wildlife.

This all sounds good but if you happen to be a tadpole or some other form of small pond life then things don’t look quite so good. The problem is water features require a pump to suck the water through, unfortunately it’s not just water that they suck up.

A tadpole.
Tadpoles – so many ways to perish, make sure your pond pump isn’t one of them.

Most pond pumps have their main water suction hidden inside a protective grill to prevent larger objects such as bigger fish and debris from getting in the pump. Unfortunately most of these grills have holes too wide to prevent smaller pond life getting dragged in.

If you research it on-line you’ll also find stories of larger life such as small fish and newts perishing inside garden pond pumps and filters. Not good.

What Can Be Done?

There are pumps on the market that claim to be wildlife friendly. We had a quick look at the websites for these pumps but found the information unconvincing and minimal so we decided to try to find a home-made solution that utilises our existing pump.

What We Tried

Before we explain what we tried I should warn you that everything we do here is outside of any pump manufacturers recommendations. Anyone of these suggestions we mention could easily damage or destroy your pump. We decided to take the risk with our pump and it’s a decision you’ll have to take with yours.

1. A Stocking

Our first attempt was to use a stocking pulled over the existing pump case and tied tight with string to seal the stocking around the pump exit pipe and cable.

This appeared to work well at first, tadpoles were seen landing on the stretched surface of the stocking and swimming away without issue. But things soon took a turn for the worse.

After a few days silt began to block the fine mesh of the stocking material and as it did it caused the unblocked areas of stocking to concentrate the suction of the pump. As a result tadpoles began to get sucked on to the stocking and were unable to pull themselves away facing a demise arguably worse than that of being sucked into the pump.

It’s a nice simple idea, but it didn’t work for us.

2. A Bucket of Stone

Our next plan was to put the pump in a bucket and cover it completely with gravel the idea being that water will get sucked through the gravel but small pond life would not. We had high hopes for this idea as the gravel would pack tightly around the pump exit pipe and electrical cable creating an effective barrier.

Sadly, this too did not work.

The gravel needed to be sufficiently course that it would not get sucked into the pump so we tried both 10 and 20mm gravel to cover our pump. After we set it up it soon became evident that tadpoles were being sucked between the gaps in the  gravel and on to the pump. This scenario was compounded by the fact that tadpoles love to wriggle down into the gravel to hide.

The other problem with this method is that you end up with a heavy bucket of stone sat in the middle of your pond that is incredibly hard to move. Not ideal.

3. Do it Yourself

Finally we resolved to build our own wildlife friendly protective cage to house the pump. The best thing we could find to do this were aquatic plant pots. These are like normal plant pots but the base and sides are perforated with a mesh of fine holes that allow water and nutrients to get through but prevent aquatic compost getting out.

The big challenge with this arrangement was always going to be how to close it up and get the pump hose and electrical cable out without leaving any holes through which tadpoles could gain access to the filter mechanism. This is tricky because tadpoles are able to get through surprisingly small openings.

We tried using two baskets put together to form an enclosed cage but finally settled on mounting the pump in one basket and closing it off with a square of filter foam cut to size and placed over the pot opening. Read on to find out how we did this…

Before we start here’s a diagram of what we did:

A home-made wildlife friendly filter cage
Diagram of a wildlife friendly pond protection cage.

Of course all pumps are different, we were working with an Oase BioPress 4000 pump here but other pumps are likely to be very different; hopefully some of the information below will be of use in your case.

What we did

As you may be able to see from the above diagram the pump outlet emerges through a hole we made in the side of the aquatic basket. To do this we used a sharp craft knife to cut a hole as close to the size of the outlet as we could.

When doing this it is important to position the pump body so as to ensure that the suction intake of the pump is as central as possible to the middle of your aquatic basket cage. If it’s not and is too close to the edge of the aquatic pot then this will result in a suction ‘hot spot’ that could cause pond life to get trapped by the localised suction. The closer the pump intake is to the middle of the cage the less chance there is of this happening.

Once the hole is cut you then need to pass the pump outlet through the hole you created and somehow secure it in place. For this task we were lucky with our Oase pump as screwed to the end of the pump outlet was a removable adapter used to connect the pump to the outlet pipe. To mount our pump we just removed this adapter passed the pump outlet out through our hole and then screwed the adapter back on sandwiching the the aquatic basket between the pump and adapter and holding it in place.

Closing Up

To provide a flat, sturdy foundation for our filter structure we placed a heavy flat stone on the floor of the pond. We used a small paving slab but any flat, level stone will do the job.

On to this sturdy foundation we placed our home-made filter cage with the open side of the aquatic pond facing downwards. To provide a tight seal between the aquatic pot and the base stone we placed a square of aquatic pond foam between them.

NOTE: Only use proper aquatic foam, using foam from other sources may introduce toxic pollutants to your pond that could kill the wildlife in your pond.

Finally we placed a heavy stone on top of the aquatic pot which pushed it down into the foam layer creating a good tadpole proof seal between the foam and the flat foundation stone.

The added benefit of this weighting stone was that it lay a few inches below the surface of the pond and provided an ideal basking spot for the tadpoles away from the shallow edges of the pond where hungry birds lie in wait.

Total Wildlife Protection?

If you want to reduce the size of the holes in your aquatic pot still further one option we found effective was to coat the outside of the pot with sections of greenhouse shading mesh (ask at your local garden centre) stuck on with aquatic sealant. It’s a fiddly job but it adds an extra level of protection.

Any very small pond life smaller than the gaps in your pot will of course be susceptible to being sucked through the pump but in most cases their small mass will probably cause them to pass unharmed through the pump anyway.

If anyone out there has any other ideas to solve this problem please let us know using the comments section below.

47 thoughts on “Tadpoles and Pond Pumps Don’t Mix. What Can You Do?”

  1. I had the same wildlife issue as you did with my pond pump and filter . My husband decided to adapt a
    ( stainless steel filter) out of an automotive parts washer filter . Then made a stainless adapter to attach it to the pump. He had the filter so it sat just below the surface of the pond . It has worked and has been in place now for years with not one single casualty . Loads of newts and frogs and tadpoles .
    The filter holes are so small that there is no way the wildlife can get stuck or get drawn into the filter .
    My way of cleaning the algae off of it is to on occasion Is to spray it with the hose. The filter gets cleaned and the water returns to full pressure. Enough to run a 3 ft water fall .
    If you want images let me know .

    Sally

    Reply
    • Hi Sally, that sounds like an impressive bit of engineering by your husband. It surprises me that there does not seem to be any truly dedicated wildlife friendly filters/pumps available to buy, I think there would be a market for them. Thanks for your comment. ENH.

      Reply
      • Hi Sally

        Please could you provide some images just found a large frog decapitated in my pump so keen to try and remedy this before the tadpoles also get sucked in once more.

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    • Hello Sally, I need to see your filter. I did have a double case around the pump but found another newt caught by the tail (dead). I cannot believe that the manufacturers haven’t created something. I have tried tights as well but they block up quickly. I hope you see this. Regards, Geoff

      Reply
    • Hi, I know it’s 2020 now but lots of us would love to see pictures of your solution to the frogs, fish, newts from getting sucked into the skimmer where they drown.

      Reply
    • Hi Sally
      Know it’s quite some time since your original post but I’ve just started researching and came across your comment re filter.
      Could you possibly send an image please? I’m keen to do the right thing by the wildlife in our garden.

      Mandy

      Reply
    • Hi Sally, I just read your solution to the filter/tadpole problem, which sounds amazing. Would you be able to send a picture or drawing about the special stainless steel filter your husband used, or any other info. I’m hoping my husband is able to make an adaption to our filter unit as well.
      Thank you very much.

      Corinne

      Reply
    • Dear Sally,

      Is there a chance that you could send me a picture of your protection over your pond pump to prevent the tadpoles from being sucked through the pump please.

      Thanks,

      Louise Cooper

      Reply
    • Hi Sally! I have a husband like yours and was wondering if you could send pics of your pump and filters? My pond is only around 2000 gallons but I love my frogs & tadpoles too much to sacrifice to the “pump guilting”!

      Sincerely,

      Alice F.

      Reply
    • Hi Sally:
      May I see a photo of it. I have to turn off my pump to save the tadpoles. I was thinking of getting a mesh to put at the end of the pipe, tie it on some way and see if that helps. I did lose a lot of tadpoles due to the suction in the pipe, but will not turn it back on until I figure it out.
      Thank you.

      Reply
  2. Hi, I would like to see a photo of your pump Sally. Im trying to improve the aeration of my pond as plants are either dying or being eaten and a small fountain (or waterfall when I enlarge the pond again) would be helpful but so far I’ve failed to see how the tadpoles would not suffer. Thanks in advance.

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  3. Sally – please, please, please send a photo. We just decided to rig up a little fountain and just before we turned it on I suddenly thought it might not mix with our tadpoles. I’d really like to get a fountain up a running so any help would be appreciated.

    Reply
  4. I’ve put a nylon drawstring Landry bag over mine but it needs clearing every few days which is a nuisance. I like the idea of the pondplant cage and foam filter. I will have a go at that one.

    Reply
  5. Most pond pumps have their main water suction hidden inside a protective grill to prevent larger objects such as bigger fish and debris from getting in the pump. Any very small pond life smaller than the gaps in your pot will, of course, be susceptible to being sucked through the pump but in most cases, their small mass will probably cause them to pass unharmed through the pump anyway.

    Reply
  6. I have used the method described in this article to protect the pump in the pond and stream I have recently built. The only problem I had was that the basket I used is very brittle and tended to crack along the lines of the mesh . In order to deal with this I used a second pot of the same size to nest over the first. This one only required a simple slot cutting in it so it could be slid on over the pump outlet after the initial assembly was in place in the pond. This also had the advantage of reducing the size of the mesh slightly. It appears to be working well, but no tadpoles have hatched so far. My only concern is that I do not think the inner pot will survive the assembly being lifted out of the pond for cleaning or maintenance of the pump so I would have to build the whole thing again in that event. I’m wondering if it would be possible to make a stronger version of this using something like stainless steel fly screen sheeting.

    Reply
    • I’m also worried about the state of my home made pump guard. I’ll be checking mine soon, my pond has a bumper helping of spawn this year and as you say the pond plant pots split easily. There’s definitely a gap in the market here for a decent wildlife friendly pump. In terms of beefing up my home made pump guard I like the metal fly screen idea. The complication, as always, is getting a good seal around the wires and tubes entering/exiting the cage. These tadpoles seem to be able to find the tiniest holes.

      Reply
  7. I have a wildlife pond with loads of newts. A friend recently gave me a small solar-powered fountain which just floats where it will on the surface. It’s a black disc about 120mm diameter. The water entry area below water level is slots only about 1mm wide, 5-10mm long. partially obstructed by the motor. Of course the fountain height is entirely sun dependant, sometimes it’s continuous, sometimes pulses, not at all if a cloud comes over, but never more than a 300mm high spray. I’m hoping it will improve oxygenation but the suction is intermittent, so with luck a newt or lesser beast could free itself. If this proves not to be so I’ll try the trick of a fine net (tights?) around the disc.

    Reply
  8. I have made a drawstring bag out of the black fabric used for weed control. The water is able to get through but when I got up this morning the pond pump had stopped. I don’t know what caused this as there was nothing stuck to the fabric so the only thing I can think of is that the fabric is too closely woven. The pump is working fine again by the way thank goodness. I have now ordered some black mosquito netting and I will make a bag again and see if this works. There are a family of newts that have bred in my pond and I am keen to keep them safe as there have been 2 that became trapped and died in the pump. I really can’t understand why the manufacturers haven’t thought of a good solution by now. I don’t mind having to clean the bag every few days as long as it safes the newts and tadpoles.

    Reply
  9. Not sure if the people who have commented already can see this, but there are literally “pond pump bags” made of mesh or stainless steel that you can get on Amazon. Just do a search. You place your pump inside of these and there will be no more dead tadpoles. You can likewise do a similar DIY hack using that screen material that’s on your windows and screen doors. They sell that in bulk at home improvement stores. Just search your store’s website. Hope this helps!

    Reply
    • I think what the original author is saying is that there needs to be enough distance between the suction of the pump and the netting/screen/choice of preventative in order to lessen what strength of the pull the tiny swimmers encounter. A mesh bag merely touching the sides of the pump itself would allow the level of approach that results in inability to swim back away from the suction, so they’d die simply from the strength of the suction up that close being greater than their strength to swim harder than the pull of the motor.

      Reply
  10. One way I have used to protect wildlife in ponds from being sucked into pumps is to wrap foam used in pond filters round the pump cage and wiring it in place.

    Reply
  11. This has been so helpful.
    Thank you for highlighting this problem and for the suggestions to overcome it.
    I have resisted a pump because I was aware of the problem of baby newts, when very tiny, being sucked into them.
    I think some company ought to try and resolve this by manufacturing a “safe” pump. I’m sure it would be a good seller.
    Any suggestions?

    Reply
  12. I just saw a post by someone on Facebook who said he had wrapped his pump in Japanese matting to protect wildlife so I thought I would pass it on here. I’m going to start experimenting myself this year as I would love to create an artificial stream with moving water for wildlife in my garden.

    Reply
  13. As an alternative to a pump bag I am trialling a reusable vegetable mesh bag that my local supermarket sells for 30p in their fruit and veg aisle. It’s a good size, has a drawstring and is made from recycled plastic.

    Reply
  14. Please can Sally send a photo of her pond pump creation as I want to save the newts and tadpoles in my pond. Thank you

    Reply
  15. Hi all, I have just purchased some green house sun shade which is a plastic fine mesh and have wrapped the filter in this and attached with cable ties and am fairly confident this will stop any small critters entering the pump

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    • I’m needing advice on a pump which will give me a gentle flow over rocks set about 30″ over a pond measuring maybe 6’x8′. I don’t want a rushing torrent! So I’m not sure what level of pump power I’ll need.
      I joined this thread to find out whether installing a pump would inhibit frogs.

      Reply
  16. Hello Sally.

    Would it be possible for you to post some photos of the system your husband designed?

    We, (the frog-lovers), would really welcome that. I’m sure the frogs, newts and tadpoles would also appreciate it!

    Thanks in advance.

    Graeme Wallace

    Reply

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