No announcement yet.

vortex size

  • Filter
  • Time
  • Show
Clear All
new posts
  • #31

    Tanks JR

    As you stat most off the things described above is not directly false or untrue. The removal action we are trying to get in a Nishikigoi pond is for us like you described.

    I was trying to point out that most off the users are in speed and outlet placement closer too industrial separation.

    Can’t and won’t discuss where vortex separation are the correct name. I have a feeling that it’s at high speed (really high) that would bee when we calculate what comes out where. Not that hard but very, very expensive (read power consuming).

    By construction many people I have the pleasure too know don’t get what the bargained for and too put insult to injury many funny claims are put out by the “perfect salesman”. Bin there dun that (once and its more than I which anyone).

    Pleased too see that I sparked an interest, it should bee done once in a while too stop old mistakes becoming new ones and too stimulate the potential Kichi’s out there.

    Hello SMGirl nice too see you up and about.
    Tone - Truls -Petter
    Vogata NI


    • #32

      Wow, it must be parallel evolution SMG ( as I am coming to almost exactly the same configuration. The primary difference is that the shipping costs drives the price of that poly stock tank up to almost $1000 here. They stuff them diagonally into a container and then pack bags of feed and other farm supplies into the holes. I wanted an 8 foot cone bottom tank but that can not be purchased through the farm supply distributors so the shipping cost alone was going to be $1000 plus the $600 for the tank purchase. My more recent plan is to dig a cylindro-conical hole and throw in a welded-seam polyethylene liner. It won't be pretty, but it gets the price back to your $400. You can camouflage ugly, but you cannot camouflage expensive.

      BTW, a friend of mine installed one of those blue flat-bottom poly stock tanks on a bowl-shaped concrete pad with a center drain. He got almost six inches of slope to the bottom of the "flat" bottom tank. Getting the center drain connected was a trick as he had all the neighbors and stacks of concrete blocks inside the tank to deform the bottom enough to screw on the bulkhead retaining nut.

      steve hopkins


      • #33

        You and I think the same things. I was going to suggest just digging a settling tank and putting in a seamless liner. I dug the cone shaped base for my tank to rest in too, the weight of the water deformed it just fine, unlike your neighbor who had to go door to door I'll bet and say will you come stand in my tank? LOL. Koi people.


        • #34

          Great Info.

          WOW, reading through all of this is really making me scared. For a first time pond builder, you all got me thinking really hard. But one thing for sure...I'm glad there is a lot of Hawaii roots here. I too live in Kaneohe just off of Lilipuna Road, Coconut Island side. One of these days soon, if anyone is willing to offer some design advice, I would be very interested in listening. I knew planning my first pond correctly was going to be a huge ordeal, but there are just too many choices of systems to choose nowadays. Thanks all. Aloha.


          • #35

            there are only three mistakes you can make.
            You will screw up if you make it too small, too shallow, or too under-filtered.
            Don't do those three things and the design will be awesome.


            • #36


              This is a small world! It also shows that I have been around

              Thai Koi-Keepers' Group


              • #37


                Went over to Coconut Is. this week and must have driven right past your house. I go through Kaneohe every week day about 12:00 -1:00 on my way to pick up the kids at school. Would be happy to stop and give you my two cents - for what little it may be worth. You should make a point of dragging Mike T. over from Pearl City too. By now his hands are probably raw from doing the concrete work on his new pond, so maybe he could use a break.

                Steve Hopkins
                cell 294-3973


                • #38

                  Slept on it

                  After stewing over all that was posted I came across a newbie question. Please forgive my ignorance, but here it goes. When designing the settlement chamber or pre-filter chamber does the designer need to take into consideration the natural direction of drain flow (counter-clockwise)? If I set up my bottom drains to enter and flow into a 5'-6' dia. settlement chamber in a clockwise rotation, is this a significantly bad design? Any thoughts? Thanks & Aloha Much.


                  • #39

                    Some still argue this one, but I once did the math to prove to myself that the Coriolis Effect is VERY weak. For all practical purposes, it is not worth worrying about. You could not notice or measure the effect in a settlement tank or koi pond. It makes more sense to base the flow direction on the most convenient plumbing route.



                    • #40

                      E for effort

                      The most important things to remember when designing your particular choice of prefiltration are:

                      1) a closed system is a trapped body of water that will build up organic material very quickly if allowed.

                      2) Koi are dirty animals in what they throw off and produce and also what they keep in suspension due to their activity

                      3) Koi live in organic water so obsession about this can become misplaced and paranoid

                      4) Having said that, high organics lead to more complex ecosystems and excess biomass.

                      5) But the presence of some organic material is usually easiest and maybe even best managed with a series of settlement chambers. This has the added advantage of the creation of transitional biofilm mix as the water goes from organic/inorganic composition to finally mostly inorganic ( ammonia laden). But of course this must all be done well or you will gravitate to a heterotrophic bacterial composition in your filters and bad things will linger close by. - JR


                      • #41

                        A while back I read a very nice account of the physics as to why the heavier particles settle in the centre. I'm pretty sure it involves an upward force. Stir a cup of tea with tealeaves in it, and a cone of tealeaves forms in the middle.

                        Centripetal force acts at right angles to the radius of rotation, so the finer particles are thrown out in a spiral and then impact in the boundary layer which is the static layer of water that it 'stuck' to the internal surface of the vortex. If this surface is rough, turbulence will occur that will destroy this smooth undisturbed layer, and the particles will not be able to sink thru it to the bottom, but will, I think be ejected back into the main flow. Peter M basically created multiple surfaces upon which static boundary films formed. You could create the same effect with a non rotating settlement with many sheets of corrugated plastic sheets a small distance apart, so the water was forced to take an undulating path thru it, forcing particles out along its length.

                        Failing all this, you could simple bin the vortex and place a microscreen over static K. That has a tiny footprint, but enormous solids removal. Plus the screen being fine nylon curtain material is dirt cheap to make.

                        CAUTION such screens will seize up solid in an hour or two if exposed to daylight. If kept in the dark, they will work brilliantly for months without that happening.


                        • #42


                          That trick with the corrigated plastic sheets would be like an inclinded plate (aka inclined tube) sedimentation chamber. There is a commercially available product for use in inclined plate sedimentation which is made of fused sheets of corrigated plastic.
                          This stuff is also promoted for biofilter use, but the square feet of surface area per cubic foot of space is is pretty low.

                          I think the principal of the inclined plate is that as water moves through these inclined plates or tubes, a particle has to fall only a short distance straight down before it comes into contact with a solid surface. The vertical height within an tube inclined at a 45 degree angle is only the square root of two times the diameter squared. Hope this makes sense - a picture would be nice. Once the particle comes into contact with the solid surface inside the tube it sticks and, as crud accumulates, it may slide back down the inclined tube or plate. It is a way to increase the sedimentation rate within a vessel of given volume and flow. These things increase sedimentation well, but are not very good at self-cleaning and are often difficult to manuall clean. If the crud is not washed away on a regular basis, the spaces will clog.

                          I still like the idea of spinning debris to a center drain where it can be removed on a frequent basis with minimal effort - or even automatically via an actuator valve and timer. Not only does this reduce labor requirements, it gets crud out of the system before it can decompose further and release more nutrients to the water.

                          steve hopkins


                          • #43

                            The difference ic that with an inclined plane the sediment settles onto the plates, and is hard to clean. Vertical plates ensure the muck drops down and can be collected as in a vortex base.

                            Easier to go with screens tho as you can get serious solids removal in a very small space.


                            • #44

                              But Bil, you must admit that CLEANING screens is not an easier go.

                              I put a submerged trash pump on a GFI and timer in my settling tank. It is the height of laziness.


                              • #45

                                if set up properly, the muck all goes down to one end, pushed by the water flow. Screens with static K will give almost total removal in the same sort of footprint as a Nexus, at a FRACTION of the price. They fail safe, unlike the answer and cost nothing to run. If the price of that is tipping the crap off the screen every day or two, I figure I can live with that.


                                All content and images copyright of: