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Fibre glass pre-formed pond?

I have been offered a second hand pre-formed, two level, fibre glass pond - 1mx1.5m (no cracks, repairs or problems). I would have to take out a bush to put it on. I would like to step up from my micro pond. I'm ok with putting in beaches of pebbles etc if it's not adequate . I don't really have space (it seems) for a pond larger than this. Even this size will be a push. The spot wouldn't get much sun - morning sun in summer equinox to equinox.

Most people seem to prefer to put in plastic liners.  Are there significant downsides to pre-formed ponds? Are there any probs with cracking in frost?

It seems a bit of a no brainer to give it a go as the pond is going free. But I would have to re-arrange the planting a fair bit to make space. Wildlife in the garden is a priority for me. We have a hundred local cats that try and stalk the area day and night.

Thoughts welcome.




  • Mr. Vine EyeMr. Vine Eye Posts: 2,338
    I think the main reasons someone would choose a liner is because it gives you the flexibility to choose your own size and shape of pond. Preformed could be trickier to install, just because you have to dig a hole the right size and shape for it and then make sure it’s filled in all around it so it is fully supported to prevent cracking.

    But I don’t think there’s anything wrong with them other than that - and if you’re being offered one for free anyway...
    East Yorkshire
  • Blue OnionBlue Onion Posts: 2,955
    I would guess it's far less troublesome than a rubber liner one, assuming you install it correctly.  Unlikely to get a leak.  I think the most people go for a liner because it's cheaper.  
    Utah, USA.
  • PosyPosy Posts: 3,601
    We had one, many years ago. The main problem was getting it absolutely level with no movement over time. The weight of the water causes some settling and you can find it really difficult to remedy.
  • FireFire Posts: 17,116
    Thanks. I'm hoping that because it is small we can fiddle with it over time if probs come up. I read that a good base of sand underneath can help stabilise matters...

    I would really hope to try and keep blanket weed out of this one.
  • PosyPosy Posts: 3,601
    Wouldn't we all! Blanket weed is a long term inhabitant of everything I do with ponds....
  • FireFire Posts: 17,116
    I didn't have blanket weed for years and then I added some online bought hornwort - and bingo, it appeared. :s I currently have a micropond and it is half blanket weed, no matter what I do. I have used the recommended sachets etc, but no joy.
  • BenCottoBenCotto Posts: 4,290
    I have found Nishikoi Clear Water to be very effective in controlling blanket weed in my pond
    Rutland, England
  • madpenguinmadpenguin Posts: 2,498
    edited March 2021
    I use Cloverleaf Blanket Answer in my pond and it works really well.
    My pond is fibreglass and I had a chap put it in and he got it dead level!
    Mine is a raised pond.

    “Every day is ordinary, until it isn't.” - Bernard Cornwell-Death of Kings
  • KeenOnGreenKeenOnGreen Posts: 1,791
    We have had two pre-formed ponds in our garden. 

    -  They have never cracked due to frosts
    - Digging the hole for them can be a pain.  Consider raising it above ground instead.  We did this with the pond at our allotment.  We surrounded it with soil, which is kept in by tree trunks.  Saved us so much work with no digging.  Photo below to show what I mean.

    - Disguising the rim of the pond is also a challenge.  When the above pond was originally located in our garden, we covered the rim with flat paddle stones, but it didn't look the best.  As you can see below, it is now planted with alpines, and sedums, and it is almost completely invisible now.

  • FireFire Posts: 17,116
    @KeenOnGreen Thanks for the details and the pics. How big is the above?
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