Determining The Water Volume Of Your Whole Reef System

Discussion in 'Water Chemistry' started by ReefSparky, Aug 12, 2008.

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  1. Eddie

    Eddie Flamingo Tongue

    Jan 17, 2010
    Vancouver, WA

    Yes, yes. Well said. That is probably why it worked for me, as I used an ICP (Inductively Couple Plasma-Atomic Emission Spectrometer) and an AA (atomic absorption spectrophotometer) with accuracies to the ppm and ppb in some cases, not ppt+-3%, maybe. I guess we don't all have access to an ICP or an AA, so I'm sorry about the metals tests mentioned before.
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  3. ReefSparky

    ReefSparky Super Moderator Staff Member

    Nov 27, 2007
    South Florida
    As promised, I used my uninhabited nano as the guinea pig for my retry at this Determining the Volume. . . .thing.

    So here's a cut and paste as a reminder to the new equasion:

    V1 = (V0 x S2) / (S1-S2)


    V1 is the unknown quantity of your entire reef system, in gallons/ounces/ml.
    V0 is the volume of RO/DI water added, in gallons/ounces/ml. (just use the same unit for the entire equasion).
    S1 is the initial salinity, in SG, of your reef tank.
    S2 is the resultant salinity.

    And here are the results.

    V1 (unknown volume) = V0 (amount of RO/DI water added) x (resultant salinity) divided by S1 (initial salinity) - S2 (resultant salinity)

    That comes to V1 (total system volume) = 2 x 32.4/35 - 32.4 = 24.9 gallons.

    To reiterate, the method works, but is probably limited to use on a newly set up tank, where swinging the SG won't wreak havoc on the tank's inhabitants.

    For some real numbers backup, the tank is 18" x 18" x 18" with a 10 gallon sump. To find the liquid volume of a vessel it's LxWxH x .0043. This would give the 18" cube tank a volume of approximately 24.04 gallons.

    I'd estimate the sump to be slightly more than 1/3 full. We'll call it 3 gallons. The sum of the tank plus the sump puts it at 27.9 gallons if you used a regular calculator.