tank volume

[Rbishop]

I would just up the temp and use table salt, 2 teaspoons per gallon, added in small amounts every 4 hours until you reach that concentration.

 

[loaches r cool]

length x width x height (all in inches) divided by231 = US gallons

Depending on the size of the substrate, a differing amount of water will be displaced. A good thumbrule is 8-12 % less for substrate and decor.

Yeah its surprising how much less water tanks hold than what they are called. For one thing the gallonage provided by the manufacturer are based on the outside dimension of the tank (including glass, and sometimes frame). My current tank project if you measure the inside openening instead of the outside dimensions, and subtract too the glass in the tank for the twin overflows, its actually about 30G less right there (no decor or substrate figured in yet).