Sump questions

Discussion in 'D.I.Y.' started by Laure, Jun 25, 2009.

  1. Laure
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    Laure Algae harvester

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    Hi



    I am considering replacing my external canister filter with a DIY sump. I have been doing some reading on the web and found some designs I like. Are there anybody here with some "favourite" DIY designs? Things you actually built and it actually works well?



    I have a few concerns. What if the power goes off? The return pipe will be under the normal water level of the tank, so a reverse siphon could start. I don't have too much space on the back of my tank for an overhanging overflow box. What other options do I have? My existing cannister filter extracts water (the inlet pipe) from the bottom of the tank. I am assuming that it is pretty good at sucking up small debris. Larger pieces cling to the sponge around the intake (sort of a pre-filter). An overflow box won't give me this function. I could probably still use the canister filter's inlet pipe for the DIY sump, but then what if there is a power failure? The siphon would continue and actually drain my tank into the sump and on the floor.



    Regards

    Lauré
     
  2. Toshi(Walter)
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    Toshi(Walter) Green fingers

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    yes it would siphon of your water, and in your case it will pretty much siphon off all your water.

    what you kan do is to build in a pipe that goes to the top and siphon's off the water at the top, that way when the power goes it will siphon off ur water but not enough to overflow your sump.

    u can also design or maybe buy something like fluval use on their inlets. that is when the pump is running is creates a siphon that lifts up a small ball, and then when the power goes of the ball will fall back into place cutting of the water.(i think this would work, but not to sure)

    if you want to shop around, i think you get a tap, or you can make something, that only opens when the power is on and when it goes of it closes again.

    these are only ideas, except for the first which i've seen, so wouldn't try them unless your 100% sure.
    hope this helps... goos luck
     
  3. neilh
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    neilh Algae harvester

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    You put the return line slightly above the over flow, so when the power cuts you don't get the reverse siphon emptying your tank. And also make sure you don't overfill your sump

    There are plans all over for a DIY overflow just using PVC piping. Best way to do it, is have the tank drilled IMO
     
  4. jannie_s
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    jannie_s Noob

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  5. Discus
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    Discus Algae harvester

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    Syphon breaks are quite easy to DIY :)
    Simply drill/burn a small hole just below the normal waterline of your tank on any hoses that might become syphons. As the water level drops, it sucks in air and the syphon is broken.
    Make sure there is enough space in your sump to take up the excess (and test it!). Also regularly check the syphon breaks to ensure that they're not clogged by algae/snails etc. (google it).

    Generally, for sump systems, an overflow arrangement is best - the easiest (with a new tank at least) being to drill a hole through the bottom, fit a suitable bulkhead and then have a standpipe. This can be combined with an overflow "box" in the corner or at the back somewhere. Depending on your anticipated flow rates, you may need more than one, or a surprisingly large pipe. I seem to recall seeing overflow calculators online. Ensure return hoses are above water level or are also equipped with syphon breaks. (if it's a ganged system with more than one outlet from a single hose, just one of them has to be above water level to act as an effective break).

    If you don't want to drill your tank, you can also easily DIY an corner/centre rear overflow box from where your syphon sucks water.

    Just watch out that when the power comes on again, the syphon can restart itself. I once saw an aquaclear powerhead's venturi hose had been attached to a slightly modified airline straight connector that was glued into place at the apex of the syphon going over the edge of the tank, which sucked out any air bubbles that accumulated there, through a one way valve, if memory serves. It was evidently vital, as removing it stopped they syphon working within about 5 minutes and a flood...

    Drilling the side of the tank for an overflow is far less effective than a standpipe in my experience.
     

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