water displacement calculator

[jonathan]

has anyone seen or know a link to a calculator that offers figuring out water volume after water displacement due to live rock? (emptying out the tank, measuring water and placing back into the tank is obviously not an option )

[Tangster]

There is noway to calculate that.. The density of different rocks would have a major effect . Why would you have to know that ? I have setup hundreds if not thousands of tanks and that was never a conceren..Just curious myself.

[jonathan]

the number may not be exactly precise but there has to be a way to determine water displacement after a certain amount of mass (live rock) has been placed into a enclosed system. i'd like to know how much water volume i have in my tank for additive purposes....i could say 15 gallons but it's probably more along the lines of 10-12 gallons...i just wanted to be somewhat sure and i thought there may be a calculator out there that could perform this....

[bouraganes]

Ther Is So Much Rock In My Tank I've Often Wordered How Much Water I Actually Have In There- A Good Question But One I Don't Know The Answer To- Things That Make You Go Hmmmmm!

[fletch]

Well I suppose you could take a container of water filled to the top and then add some rock that you have weighed to it and than measure the amount of water that was displaced by the weight of the rock you added to get an estimated formula. John

[jonathan]

Originally Posted by fletch

Well I suppose you could take a container of water filled to the top and then add some rock that you have weighed to it and than measure the amount of water that was displaced by the weight of the rock you added to get an estimated formula. John

thanks john (...or fletch), i appreciate the feedback. i'll have to give it a whirl.

jonathan

[Ph4Y5e]

the GARF site has a displacement calculator....Geothermal Aquaculture Research Foundation Home Page

[inwall75]

Originally Posted by Ph4Y5e

the GARF site has a displacement calculator....Geothermal Aquaculture Research Foundation Home Page

I went and looked at that calculater. While I thank you for finding it an sharing it with others, Tangster is correct and it's not really useful. Fletches way is pretty much the only way. Here's why. The density of LR will determine it's mass. I have HUGE pieces of Marshall Island and Fiji that don't weigh nearly as much as a lot of the Florida maricultured LR in much smaller sizes. The maricultured rock is not very porous at all and is responsible for people thinking they need to have large quanties of rock per gallon of water. If you have porous rock, much of the water will reside within the rock as opposed to around it. Internal surface area means more space for bacterial biofilms and less mass needed for a particular bioload.

[Dador]

Curious if you came up with something of a constant for your rock that we might be able to use for calculation. Did you come up with a a formula?