Waterflow and Stressing glass

Discussion in 'Pumps and Waterflow' started by Hill, 19 Nov 2007.

  1. Hill

    Hill

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    Hey guys just wondering. Would the high water flow rates of a reef tank add to the stresses on the glass? I mean with turn over rates of 20x or more that is a lot higher than FW or FOWLR.

    Any opinions?
     
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  3. viper357

    viper357 Admin MASA Contributor

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    Sorry Hill, I moved your post into a new thread as I think it is quite an important question.

    Good question indeed, also with regards to pointing rather powerful pumps towards a pane of glass to aid in dispersion of the water flow, does this practice place more stress on the glass or rather the silicone joints?
     
  4. jacquesb

    jacquesb Retired Moderator

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    Hi Hill/Dean - I am not sure that I can really add to the question as such, BUT, taking into account that some people run their systems at 120 times water turn-over per hour, and don't as such increase their bracing - I am not sure whether the amount it does increase, should the actual pressure increase, be enough to be worried about....
    BUT, then again - who am I ;-)
     
  5. Tridan

    Tridan

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    Ok not going to get scientific here but in easy terms what happens is that the flow does put a bit of extra pressure on the glass and joins, but the best part is it actually releases most of the pressure upwards, kinda like increasing the hight of your water column.

    Its kinda hard to see but if you switch off all your pumps and mark your hight then switch them back on and check the level diff. its not much but sometimes you can see it.
     
  6. leslie hempel

    leslie hempel Moderator MASA Contributor

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    im not convinced. you are working with a contained pressure...
     
  7. Tridan

    Tridan

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    Less how can it be contianed if the top of your tank is open
     
  8. Galibore

    Galibore Retired Moderator

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    Good question. Common sense say it must. But how much I wouldn't know.
     
  9. Mekaeel

    Mekaeel Moderator MASA Contributor

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    i honestly think its putting alot of pressure against the glass,but not that its such a huge concern,hey no pro just my 2cents.excellent thread,gonna be following closely.
     
    Last edited: 19 Nov 2007
  10. Alan

    Alan Admin MASA Contributor

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    I think it may, but with the size pumps we use it must be very slight.....i have been wrong before, lets see.
     
  11. DragonReef

    DragonReef

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    I doubt the actual pumps themselves would cause pressure.

    The only time pumps would cause undue stress is if they are setup as a surge device or like the Tunze wave makers. These move large volumes of water side to side which does put pressure on the glass and silicone joints.
    Tanks have burst from Surge / Wavemaket devices.

    Normal powerheads wont cause problems. Water will follow the path of least resistance and will bounce off the sides and well upwards.
     
  12. dbdouble™

    dbdouble™

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    I have to agree with Anthony here. IIRC Tunze have a disclaimer in the brochures that come with their Wave Box as this product moves a huge portion if not the entire column of water from one side to another. Especially concerning for those with larger tank volumes.

    B
     
  13. Hill

    Hill Thread Starter

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    My original post was originally posted in another thread. So I need to explain a little.

    This was in response to someone who had a 1.5m tank made from 5mm glass. Now the tank held for months as a FW tank. But as we know those have low flow.

    Now in science we learn that for every action the is an equal and opposite reaction. So now lets say the tank glass panes and silicon are close to their limits. Would the tank experience extra stresses due to the higher water movement.

    A glass pane would absorb some energy and the rest would need to be deflected. Ok I am really tired so I hope this makes a little sense.
     
  14. Mike

    Mike Retired Moderator

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    i have heard that the wave machines put stress on tank sides, but it believe the biggest tank killer is when they are set up not level, the glass and silicone together are immensely strong - assuming that the glass is correctly sized to begin with - but when the tank is on a slight slant all the pressure will be deflected to the end/side that is the lowest.
     
  15. leslie hempel

    leslie hempel Moderator MASA Contributor

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    put a drum of water on the back of a bakkie full and you have more controll over as opposed to if it were it half...

    my logic is that you are never really pushing all the water in one direction long enough to put serious strain on any one given piece of glass this with other pumps pushing against one another must neutralize the pressures to a large degree....

    were it a rocking motion and from one side of the tank to another i feel it would be a different story...

    i feel the system is a contained pressure because for example if it can only hold 1000lt whatever is put in (rock, pumps,magnet cleaner) will displace water to equate to the equal pressure on the glass...

    im not talking pinpoint pressure (sharp rocks on base) im talking displacement....

    my 2c
     
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