Welcome to Koi Forum. Is this your first visit? Register
Results 1 to 5 of 5
  1. #1
    Member Rank = Tosai Kris's Avatar
    Join Date
    Apr 2019
    Location
    North Lincs
    Posts
    36
    Thanks / Likes
    40

    Question on pond returns and skimmer placement

    Evening all,

    I'm hoping for some advice on how many returns, where to place them, and where to put a skimmer please. It's a block built pond, to be fibreglassed, and roughly 18k litres. I've built up to point where I now need to put the returns in before I can go any higher, and plan for the skimmer. Coping stones will go on as well (not shown on drawings) but I'm at 14 blocks (155cm) at one end and 13 blocks at the other now, and will go to either 17 blocks (188cm) or maybe 18 blocks (199cm) all round.

    The drawings below are based on 17 blocks and would give me approx. depth of returns at most 40cm at one end and 50cm at the other (if I cut into the blocks already laid). If I went to 18 blocks I could get the returns another 11cm lower from the water line. The first question is, is this deep enough for returns, could they be higher up (less deep)?

    The second question is do I go for two returns at one end, or two returns at both ends? Ball valves to be used to turn diagonal pairs on or off, the idea being I can change flow direction weekly. OTT, nice to have or completely unnecessary in this size of pond?

    Four returns:
    Pond-top-view-returns-option1.pngPond-south-end-view-returns-option1.pngPond-north-end-view-returns-option1.png

    Two returns:
    Pond-top-view-returns-option2.pngPond-north-end-view-returns-option1.png


    The third question is where would I put the skimmer? On a side wall (1, 2 or 3), on the north end wall (4), or anywhere else you fancy? It's a block replacement type affair from JBR Plastics.

    Pond-top-view-skimmer-options.png

    Any suggestions, help or comments will be gratefully received

    Regards,

    Kris.


    Attached Images Attached Images

  2. #2
    Member Rank = Tosai Kris's Avatar
    Join Date
    Apr 2019
    Location
    North Lincs
    Posts
    36
    Thanks / Likes
    40
    Afternoon,

    Can anyone offer any advice or comments please?

    Cheers,

    Kris.

  3. #3
    Senior Member Rank = Hassai Twhitenosugar's Avatar
    Join Date
    Apr 2020
    Location
    Europe
    Posts
    808
    Thanks / Likes
    1291
    Hi.

    You probably don't want any returns or skimmer on the side you have your window as it'll make that wall look a bit ugly. Better if you have them on a wall so the pipework is hidden from where you will most likely stand to look at the pond.

    In terms of skimmer, its always a job to know where exactly to put them as it's hard to know where any dead spots will be. But ideally the skimmer is situated to where you think any flow and a prevailing wind would push flotsam ( usually from the SW, but it might come from a different angle in your garden depending on what there is around the pond e.g. walls, buildings, hedges etc...)

    On my 13k litre rectangular shaped pond. I have my returns on the back wall in the right hand corner, so these push water across the narrow right hand end of the rectangle and then along the front wall i.e. across my window. Tbh by the time the water gets to the window the flow from the return drops off. I have my skimmer in the back left corner i.e. in the last corner before getting back to the skimmer, if doing a lap of the pond.

    If you have your returns lower down in the water column then the 'push' from your return will have less of an impact in terms of moving the surface water about.

    The other thing to consider is making sure you place both returns and skimmer in places you can get to if you need to turn your valves off or get your hands in the skimmer. And also so that you can run your pipes to and from your filters.




    Sent from my Pixel 4a (5G) using Tapatalk
    13,000L fibreglassed raised pond with window

  4. Thanks Kris Thanked / Liked this Post
  5. #4
    Skimmer locating is a black art based on my not always successful experience.
    You would think that if the prevailing wind is from the SW the skimmer should go somewhere opposite.
    Maybe. If your pond has a fence nearby, a shed or even low jump guards, these can set up a reverse eddy which sends the surface of the water in the opposite direction you would expect.
    In an ideal world you would be able to fill the pond, see where debri collects and go from there, but of course it's not that simple.
    My experience of skimmers in ponds and swimming pools is to consider using two skimmers at opposite ends (though I didn't do this - too much effort) and/or making sure that the skimmer has a very good surface flow - that is you can see the surface of the water entering is flowing fast enough to properly break the surface tension.

    Returns can also be a bit hit and miss, but generally if you can encourage the whole pond volume to circulate in one direction this usually helps.
    If you stir your sugar into a cup of tea the undissolved grains collect in the middle - presumably near where your bottom drain(s) will be in your pond, so that is to be encouraged. You might get counter eddies in the corners, but again, not always.
    If you are concerned about returns disturbing the surface too much you could always add a short directional bend to the outlet. Could also help in case of unexpected dead spots collecting debris.

    That's the limit of my experience I'm afraid - any more would be conjecture.

    Last edited by Ukzero; 20-04-2021 at 03:47 PM.
    My DIY ponds from 1988 until present day.
    All can be found here:
    https://www.ukzero.com/pond.htm

  6. Thanks Kris Thanked / Liked this Post
  7. #5
    Member Rank = Tosai Kris's Avatar
    Join Date
    Apr 2019
    Location
    North Lincs
    Posts
    36
    Thanks / Likes
    40
    Thanks for the comments so far.

    The pond will be reasonable sheltered as the bungalow is close the W and S side of the pond and we have a high hedge and a couple of trees to the E side.

    House-pond-overview.png

    I'm planning on cladding the outside of the pond so no issue in hiding the pipes for the returns.

 

 

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
All times are GMT +1. The time now is 09:08 AM. Online Koi Mag Forum
Powered by vBulletin® Version 4.2.3
Copyright © 2021 vBulletin Solutions, Inc. All rights reserved.

vBulletin Improved By vBFoster® (Lite Version), © UltimateScheme, Ltd.