Stocking Question/Brainteaser

[Icewing726]

So I bought a 150 gallon tank with a 55 gallon sump.

Then I realized this tank at max will only hold just shy of 140 due to glass thickness. I'm sure this affects the 55 as well in some way as well.

So my stocking questions:
1) First, do I count the sump towards total water volume even though it's not swim space?
2) Do stocking sites that recommend tank sizes mean the tank advertised size (in this case 150), or does it actually mean whats in the tank?
3) Should the advertised tank size have been lower (did I get ripped off)?

 

[Drix]

1. Yes- water volume has to do with how much H2O you have in your water column, changing the amount of time it takes for a chemical imbalance to progress.

2. It means display size, if you have a 3' moray eel in a 20g tank with a swimming pool as a sump that moray ain't going to be happy.

3. I'm not sure.

 

[thegrun]

1. True water volume includes the sump, but you need to deduct for rock, sand and equipment water displacement. My 120 gallon display and 70 gallon sump have a true water volume of 145 gallons.
2. Stocking size refers to the display tank size only, but you can use the 150 gallon as your tank, not the 140 gallons; the sizes given are looking for swimming room in your display tank.
3. Most standard sized tanks are actually a little smaller than their stated sizes, even if you measure the outside dimensions of the tanks, not the IDs.