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  1. #1
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    live rock density?

    I am trying to calculate the density of LR and i was wondering if marshall, fiji, tonga have different densities. I am asking this so i can figure out how much water i have in my tank.

  2. #2
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    marshall is more poreous than fiji boulders.

  3. #3
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    Nono, i am asking for a numerical value so i can calculate exactly the amount of gallons of the rock. ex: 100lb marshall= 45g or 100lb fiji=60g. i can only calculate this if i have the appropriate density of each type of rock. By the way, i sorted things out with eric. I was actually surprised to what he told me. call me for more details.
    "The significant problems we face cannot be solved at the same level of thinking we were at when we created them."
    - Albert Einstein (1879-1955)

  4. #4
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    ok mike ,multiply the wirght by the size of the sun then divide it by 348765,then add 2 thats your answer

  5. #5
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    Diameter, radius, circumference or volume of the sun? -

    If you really want to find out, you could do the experiment. Place the LR in a container of distilled water (you could use salt water but the math gets a bit trickier to get the specific gravity although density would be OK). Measure how much the water level increases. Use that to figure out the volume (in liters) of the rock which gives the weight of the same volume of water. Weigh the rock. Divide the rock weight by the weight of the water displaced to get specific gravity. Divide the rock weight by the volume to get the density.
    Nick

  6. #6
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    Density equals mass divided by volume. Weigh some rock, place it in water, determine displacement.

    Unfortuntely, you can't really do it on live rock, as the best way to measure is to completely dry a piece of rock. Break off a piece of rock you want measured, then dry it fully (this will kill whatever life is on it). Weigh this piece as acurately as possible. Place the dry piece in water(covered container so there is minimal evaporation), allow it sit long enough to absorb water. Determine the displacement of water in the container. This will give yo the formula to work out the density.

    Keep in mind that rock from (for example) Fiji will have similar density if it was created with the same compounds, same volcanic formation, came from same rock shelf, etc. If it came from the other end of the region, it will probably have a different density.
    The short answer is: there's a way,l but it's not acurate, and it's a pain in the arse.

    Edit: Damn, Nick beat me to it

  7. #7
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    I can't believe no marine biologist/ecologist/scientist has done this experiment with all different types of lr. I guess i will only really know the day i empty my tank. i really think that there is a max of 75g in my 135.
    "The significant problems we face cannot be solved at the same level of thinking we were at when we created them."
    - Albert Einstein (1879-1955)

  8. #8
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    ok so empty your tank and let us know.so are you going to do this right now.hahahahahahahahahahha

  9. #9
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    Mike i wish you and your family a merry christmas and a fantastic new years

  10. #10
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    1G (US) of water weighs about 8 lbs. If your 125lb of LR had the same density as water, it would only occupy 125/8 = 16G. SInce LR has a higher density than water (likely around 2), the volume of the LR will be even smaller (likely about 8G).
    Nick

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