Calculating Water Volume for Dosage

[Hugh Mann]

I'm just wondering, does anyone take into account the displacement of rock and sand when figuring water volume to achieve the proper dosage of anything, be it meds, minerals or what have you? If so, how do you go about doing it?

I highly doubt my 55 gallon has exactly 55 gallons of water between the HoB filter, skimmer, rock and sand.

 

[Tathamet]

I'm just wondering, does anyone take into account the displacement of rock and sand when figuring water volume to achieve the proper dosage of anything, be it meds, minerals or what have you? If so, how do you go about doing it?

I highly doubt my 55 gallon has exactly 55 gallons of water between the HoB filter, skimmer, rock and sand.

I believe there are calculators for exactly this. You input your tank dims, sump/refugium dims, water line from the top of the tank, weight of rocks/sand and it calculates it for you. Can’t remember the website I was on but I was able to google it fairly easily when looking awhile back.

 

[Tathamet]

I believe this was the site I used.

Aquarium System Volume Calculator

 

[Hugh Mann]

I actually just finished using that one. Thank you very much. Very helpful.
~50 gallons.

 

[Tathamet]

I actually just finished using that one. Thank you very much. Very helpful.
~50 gallons.

I haven’t had to dose anything in my tank yet but I would recommend dosing maybe a half dose at first and testing just to make sure the math checks out. Better to add less than too much.

 

[JCTReefer]

The only true way is upon set up. With all rock, substrate, equipment in place. Then measure as your filling the tank and sump. This is what I did on my little 54 gallon with 15 gallon sump. Actual volume is only 57 total gallons. Doing it this way will get you close. Of course it’s only practical doing it upon start up. I actually weighed all my rock too. I’m crazy like that. Kind of time consuming though. But then coral grow, displacement changes a bit. So many variables really. You can see if your volume is close by your results on dosing also!!!