Calculating water volume

[averagesteve]

Hi all,

I have a quick question, if I'm adding a product to my tank that says "add 1tbsp per 10 gallons of water" and I have a 29 gallon tank, do I:

Add 3 tbps

or

Calculate that I have 30 pounds of live rock, 30 pounds of sand, which displaces about 7 gallons of water, leaving me with 22 is and add 2 tbsp?

 

[Peace River]

Based on the directions, I would base the amount on the water volume and not on the tank size. Good luck!

 

[Auquanut]

^ Agreed. I figure what I think the water volume is , then estimate on the low side. Better to dose too little than too much. You can always add later, but you can't take away.

 

[3dvice]

I'd just split the difference between tank volume and estimated water volume. Then your dose is only off by about 12% at most either way.