Actual volume=tank volume-displacement from gravel, rocks...

[afFISHionado]

Just curious....Does anyone take into acount the volume displaced by driftwood, large rocks and all their gravel when dosing their aquariums with treatment?

[fishfreek]

I think its a bit to exact. Your probably going to spend more energy calculating out 'acutal volume' than its worth.

[TankGirl]

Most medications are not going to have adverse effects if not dosed exactly. You are absolutely right, though, because I think many people would be surprised to see how much water is displaced by the substrate alone.

[afFISHionado]

Hey - I figure nothing wrong with being anally-retentive when it comes to my fish.

[An t-iasg]

Hi, I took this into account when medicating my tank. But it's easy for me because my tank is so small. It's 5 1/2 gallons, and I remember when I filled it that it actually held 4 1/2 gallons. I decided that I could still medicate at the 5 gallon dose, and the fish were fine and got better quickly.