I don't know if this has been done, but is there a formula or any common way to measure the volume of medium filled grow beds? I have figured the volume of the empty bed and am trying to estimate for the size fish tank I need. Hydroton will be my medium, but I need to find the volume after displacement in a ~150 gallon bed.
Thanks for any help if my question is even relevant.
So you know the overall volume of your grow bed? And you are wondering how much water it will take to flood that bed once it is filled with media right?
Well instead of trying to tell you an exact amount (some people have estimated it takes about 40% of the volume to flood it.) I'll just say when you figure how much water volume you want to have available for flooding a grow bed I generally tell people 50%
So if your fish tank is the same volume as your grow bed, then when your grow bed is flooded you will still have at least 50% of the water still available for your fish. Or if you make a 2:1 grow bed to fish tank system and have a sump tank, make sure the sump tank can hold at least 50% plus some extra (since most pumps can pump a tank completely dry without burning out) of your total grow bed volume.
does this help?