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fish tank solids

Discussion in 'Aquaponics Ideas' started by tuppy, Aug 18, 2012.

  1. tuppy

    tuppy New Member

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    just wondering instead of brooming the bottom of fish tank,would i be able to place pipework similar to swirl filter in the fish tank to give a swirling action from the pump,thus moving the solid around,would this work and not harm my jade perch..
     
  2. bigdaddy

    bigdaddy Super Moderator

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    Hi Tuppy,

    If the pipework and alterations allow the water to be moved slowly then, in theory if you place the pipework on the outside of a round tank going anti clockwise the solids should gradually move to the middle... you could then Use a large aquarium Gravel cleaner to remove the solids, into some watering cans and pour it over your dirt garden, then top up the fish tanks with clean water when required( I did that with my 500 litre tanks and it worked well).

    You should not be moving the solids quickly or harshly as they can break down and create far more "fines" in your system then you want..Fines are very difficult to eliminate.

    Cheers
     
  3. Murray

    Murray Site Admin Staff Member

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    It is good to have a circular water motion in your tank if you can, even if it is a rectangular or square tank,, it is a good thing to do. Obviously it is more difficult in a rectangular or square tank, but good to do if you can set things up that way.

    It is no trouble to broom the tank once a week in a home system. If it was of commercial size then you might try to have system design to accumulate and remove solids.
     
  4. Walks-In-Storms

    Walks-In-Storms New Member

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    It must be that "great minds think alike," because I started experimenting with this idea at the same time I built my versions of a swirl filter. I used a simply siphon made from hose to clear our the solids. Is there any reason that wouldn't work with the main fish tank, too?

    My fish tank is a 260 gallon - 1000 liters - galvanized stock tank, and its round ends have suggested to me that water flow from my sump pump should be such that it induces a circular flow (the better to send solids to the center). Had I been smart enough at the outset, I would have raised my tank a bit, enough to have a functioning drain at the center for the purpose of draining the tank.

    Just "thinking out loud" a bit .... :24locos:
     
  5. bigdaddy

    bigdaddy Super Moderator

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    No WIS, no reason at all why a siphon hose wouldn't work... apart from the very same reason the gravel cleaner won't work and that is, if the walls of your fish tank end up being too high for the siphon to work...The gravel cleaner is just an elaborate siphon... a siphon with a lightweight check valve built in so you can shake the body of the cleaner to form a siphon rather than adding water to the bottom of the hose....

    The other thing, and I don't know if it works or not..many an argument has occurred over this but...technically in the Northern Hemisphere, they say you should have your water going in the clockwise direction in your swirl, in order to acheive your solids working their way to the middle, and in the Southern hemisphere anti clockwise...I don't really know that it makes a great deal of difference in practice but that's what they suggest in theory anyway. You may want to check out some of the Koi sites when they start talking about filtration on that one....I just do what they suggest and it worked for me ....

    Cheers.
     
  6. Murray

    Murray Site Admin Staff Member

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    You are just going to love this BD, but it is the other way around.
    Cyclones rotate clockwise in the southern hemisphere and the lowest pressure is in the eye or middle.

    When solids arrive in the circular tank they are carried along at speed by the rotating water at the outside of the tank because the water flow is travelling at it's greatest speed there. Moving in toward the middle where the water is actually slowing down, the material can precipitate to the bottom and therefore most (not all) will accumulate in the middle.

    The journey of the water containing the solid material towards the middle is assisted by the water outlet being in the exact middle of the tank, but at the top of the circular tank.
     
  7. RupertofOZ

    RupertofOZ New Member

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    Hurricanes and Typhoons rotate anti-clockwise... cyclones, clockwise...

    The lowest pressure is in the eye or middle.... regardless of the rotational direction...


    This is due to the earths rotation... and known as the Coriolis force...

    The Coriolis force on earth only works on very large scales. It doesn’t affect such small things as toilets and sinks.... or fish tanks...

    You may have heard that toilets and sinks swirl counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere due to this force...

    As cool as that would be, it’s just not true. The way the water swirls has to do with a number of conditions such as the shape of the bowl and the way the water enters the bowl.... or fish tank for that matter...

    It doesn't matter what the direction of the rotation in the tank is...the solids will drop out to the centre...
     
  8. Walks-In-Storms

    Walks-In-Storms New Member

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    Actually, gentlemen, I think (actually, I know - having conducted tornado operations for insurance companies and state government agencies for many years, being a pilot and a tornado hunter whose close-up photos of tornadoes have been widely published) you'll find that all low pressure (cyclonic) storms rotate counterclockwise in the northern hemisphere. Rupert is correct about hurricanes where the Coriolis Effect is concerned, but tornadoes are too small to be so affected. Tornadoes are spawned by extreme pressure gradients near fast-moving fronts (cold, heavy air "rubs" across warmer air, and forces its way under the latter). Thunderstorms develop in warm, moist air in advance of eastward-moving cold fronts. It is the thunderstorms that produce tornadoes.

    Cyclones aren't tornadoes, incidentally - they merely have to do with tornado formation.

    Rupert is also correct concerning swirling water. The Coriolis Effect, and hemisphere location, have no effect on swirling water. Rupert correct again concerning solids action in a vortex - I've conducted literally dozens of experiments. More, anyone who tries it will find the best swirl filters depend on speed and depth (closely related, by the way - just like a tornado) of the vortex, not a helix or sloped wall (sloping the wall or surface is one way to make the vortex more rapid, but water pressure works better). My filters (there are pictures here elsewhere) have proven very effective, the two three foot lengths of four inch (100 mm) pipe remove several quarts of "solid" waste every two or three days.

    Here's a "link" about tornadoes (just thought everyone might like to know, or find it interesting....). http://www.nssl.noaa.gov/edu/safety/tornadoguide.html
     
    Last edited: Aug 20, 2012
  9. bigdaddy

    bigdaddy Super Moderator

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    Yes it's nothing for me to the direction wrong...Whistling

    I did put my elbow on my swirl filter both ways and really found no difference in the amount of solids in the middle so all of your explanations makes sense to me..The general point I was trying to male is it is good to have a circular movement of water in a filter(having said that...I now use a radial solids separator which IMO is far superior to the swirl) .

    I think I also need to reiterate when dealing with solids and trying to filter or separate them out in a swirl, it is best that the water in the swirl filter does not move around to harshly as harsh water movement can cause the solids to break down into fines....and the idea is to minimize as much as possible the amound of fines in the system..

    Thanks for the link WIS...I do find that interesting...Here is a question for you talking about cyclones....Why is it when a cyclone moves over you, the wind travels one direction, then when the eye is over you you have a period of no wind movement then when the cyclone continues in the direction it always has the wind changes direction and goes the opposite way?:confused:

    Actually I know why, but if others want to explain it ..feel free....It's just a little bit of useless trivia again...:(.

    Cheers.
     
  10. davidl

    davidl Member

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    Aaaaannyyway....
    Getting back to the original question of getting solids out of the fish tank.

    I find that a simple Solids Lift Overflow (SLO) works great. I've never had to clean my actual fish tank. I've had to clear out a bunch of my pipes due to too much bacteria growing in them, but not the fish tank. Essentially a SLO is simply having piping on the inside of your tank going from the overflow hole near top to the point(s) where you expect the solids to mostly collect, ie the middle. Just ensure you do not create a siphon by using a T-piece instead of a 90 deg bend when joining the top horizontal piece to the vertical pipe. This allows air to be sucked in at the top to break the siphon action when the water level goes below your overflow outlet level. If you make a siphon instead of an overflow you are at risk of siphoning all of the water out of your tank.

    Incidentally, while a swirling action is good to have to gather the solids together, I find that the fish swimming around near the bottom mess that up most of the time anyway. But then the SLO still works through enough water to gather up the solids and keep the bottom pretty much clean.

    edit: if your outlet hole is in the bottom of the tank you may find that having a pipe on the inside surrounding the outlet helps, as they are typically not flat. Have the top sealed off and cut some gaps in the bottom so it is sucking up water from the very bottom of the tank. You could make it all fancy by having a bunch of pipe at the bottom sucking water up from a bunch of places in the tank, but I think that is not needed. I'm assuming you have the correct piping on the outside of the tank already in this situation to prevent the tank from completely draining.
     
    Last edited: Aug 20, 2012
  11. Walks-In-Storms

    Walks-In-Storms New Member

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    EXCELLENT! (Meaning, of course, I agree...). I wish I had raised my fish tank off the concrete slab I poured for it, and my wife and I were just this morning discussing pros and cons of raising the fish tank in order to put a drain under it. The fact is, however, that my filters are working so well that as long as I keep solid material from outside the system out of the tank, I shouldn't have a problem. Work on digging a sump for my own CHOP design goes forward today, and we have high hopes for a very efficient and productive aquaponics system. My learning curve has been less than exemplary, nonetheless.

    Thanks again. :p
     
  12. Walks-In-Storms

    Walks-In-Storms New Member

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    The siphon idea worked eminently well, but for the fact that there proved to be very little on the bottom of the tank. I now have both a very clean aquaponic fish tank and a very clean backyard fish pond. The sediment tank I installed in the latter accumulates pounds of both silt and goldfish "poop," and that's another idea for aquaponics. If you circulate (clockwise or otherwise) water around a fish tank equipped with a sump (I've used a one meter long, 15 centimeter PVC pipe), it will collect most of the heavy stuff. I'll use a pump (being purchased today, matter of fact) to pull the stuff out the bottom, but I wish I had just installed an evacuation route in the first place ("Too soon old, and too late smart").
     
  13. Walks-In-Storms

    Walks-In-Storms New Member

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    Well, if you consider the vortex at the bottom of your bathtub when it drains, you'll see the answer. Like a hurricane, a tornado has an "eye" - a place where low pressure results in little or no wind at all. The wind is actually blowing in a circle, such that its direction where you are concerned depends on where you are when it hits you. The speed of the wind has to do more with resistance to its flow (fluid dynamics) than anything else - "resistance" having much, in turn, to do with density (humidity and temperature of the air) it has to move. The wind speed of a tornado depends much on how fast it got going before atmospheric "lifting" (same thing that raises a glider) stood it up. That means ("in turn," again) the difference in temperature and humidity of the cold front and warm front whose incestuous relationship spawned the storm.

    You may be interested in knowing that I was among the very first (1966 Belmond, Iowa - http://www.youtube.com/watch?v=pQA0DO3fpcQ) "storm chasers." I tracked that storm from about a mile distance, after having had it drop out of the overcast a little over one hundred yards away. I tracked the Charles City, Iowa Storm a little later, too - that one from a similar distance, and was running on foot behind it when it plowed down the main street of my brother's home town. In the years that followed, I tracked storms in Iowa, Illinois, and Indiana also. A friend and I tracked in an airplane (Cessna 172) four (I'm not joking) tornadoes (all in the sky simultaneously) which never touched the ground, that at the behest (we were landing when called by the tower to ask if we could see any tornadoes) of the National Weather Service Station in Mason City, Iowa.

    Again, they don't call me "Walks-In-Storms" for nothing (some wonder why it wasn't "Idiot Who Walks-In-Storms").

    Just thought you'd find it interesting (and, of course, with apologies to those not interested and so intent upon "off topic")
     
  14. bigdaddy

    bigdaddy Super Moderator

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    Hi Walks in Storms,

    I'm interested... I don't think you are off topic... It is related to cleaning the tanks...We are using that action in a swirl separator...Which is one way of reducing the solids in your fish tank.

    Thanks for posting the links...

    Cheers.
     
  15. davidl

    davidl Member

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    WIS, you do not need to have a pipe coming out of the bottom of your tank to do this.

    There is a basic diagram of a SLO that shows what I'm talking about here
    [​IMG]
    This shows how to have an overflow hole near the top of your tank that draws the water up from the bottom of the tank.

    I have mine arranged slightly differently, but it does not perform any differently. This is a pic showing my air break. I have a vertical pipe in the centre of my tank going down to the bottom to suck up stuff from there. The only reason I did it with the air break on the outside, instead of a T-piece inside was because of poor planning and it works like this with the parts I purchased.
    [​IMG]
     
  16. davidl

    davidl Member

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    another good pic of a slo. Except the outlet hose is too small.
    [​IMG]
     
  17. oceansgreen

    oceansgreen New Member

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    ive seen sand for salt water tanks that contain microbial's that will quickly digest the poo and turn it to nutrients, i would assume they have some for freshwater fishies as well, unfortunately i dont know a name or a link, but the idea is to just have a sand bottom with plenty of microbial life to break things down as fast as they come:)
     
  18. Walks-In-Storms

    Walks-In-Storms New Member

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    Superb! That's exactly what I intend to do when I complete "morphing" my system (I, as well, did some "poor planning, you see...) to a CHOP like I've already diagrammed here elsewhere (I also propose to put the vertical pick-up pipe at the geometrical center of the tank). As is my customary practice, I'll first put the pipe together without gluing, see how well things go, and then adjust.

    Meanwhile, it's great to hear that someone else has the same idea. Obviously, you're "on top of things." Many thanks. :p

    P.S. I still wish I had a drain in the middle bottom of that sucker - just not sanguine about the pick-up tube getting all the sediment. In my view, you can't have too much access to any system having to do with water and fluids.
     
  19. davidl

    davidl Member

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    Thanks wis.
    Note that you do not need to glue the pipes inside the tank, ever, because they do not need to be fully air or water tight.

    Also, since it is an overflow it will be low pressure, and many of the pipes on the outside do not need to be glued either. None of my pipes are glued. I've just put some teflon tape (aka plumbers tape) around the joins and it hasn't leaked in the 2 years I've had it like that. The reason so many people are gluing pipes is because of all the joins they have on the pipe coming out of the pump. Those are high pressure and need to be glued. This is another reason I do not like the chop2 design. CHOP1 allows you to have a single hose coming out of the pump and going to the fish tank with no joins and no gluing, just a clamp to secure the hose to the pump.

    The main reason I do not like chop2 is that it requires considerably more electricity to operate it, due to the fact it is pumping the water to the fish tank and grow beds in parallel, requiring a bigger pump with increased flow rate. I've done the math showing how much of an increase this is on another thread somewhere...
     
  20. Walks-In-Storms

    Walks-In-Storms New Member

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    Ha! You have me chuckling. One of the problems I've encountered with this otherwise excellent site has to do with the fact of continent-to-continent, hemisphere-to-hemisphere (even), ecosystem-to-ecosystem communication; Atmospheric conditions in the Sahara, to say nothing of logistics and supply availability and the like, in short, vary somewhat from those in Greenland (or Antarctica).

    Somewhere else here today, a subscriber asks another "What does one need with a greenhouse in the Caribbean?"

    I do, still, sometimes (even often) connect schedule 40 polyvinylchloride ("PVC") pipe without using glue. That's even after having all the water in a hydroponic system drain into the yard when the son's heat and shadow from the house combined to expand and shrink the pipe (sun on one section, shade on the other), while expanding the other. Presto, the weight of the pipe (bowing more as the sun - 46 degrees Celsius that day - heated it) pulled it out of the elbow and bye-bye water. I also have at the moment part of another hydroponic system leaking at an unglued joint. I've just drained it, and when it has dried out, I'll go out and glue the beggar together. :frustrated:

    I glue a lot, the result being I have barrels full of PVC pipe scrap for other projects. For the amount of pipe I use, I'd just as soon glue.

    Nevertheless, you remarks are much appreciated, especially as has to do with your system. How do you pump the water (one of my aquaponic wars battle scars has to do with the miserable quality of the pumps I can buy - inasmuch as the cost couldn't be as much as I've already spent on pumps, I'm about to have Murray ship me one from Aussieland)? :p
     
    Last edited: Aug 26, 2012

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