Stocking: Volume vs. Footprint

[zdrc]

The freshwater hobby has moved from stocking based on gallons to stocking based on tank footprint. The idea is that footprint gives a better judge of swimming space than volume.

In the saltwater hobby, volume is still used when determining stocking with little discussion of footprint.

While tank volume and footprint are correlated they can be surprisingly different. For example, a 60 gallon cube (24"x24"x24") has a footprint of 576 square inches while a 40 gallon breeder (36"x18"x16") has a footprint of 648 square inches. Footprint would indicate that the 40 gallon breeder could be stocked 12% more than the 60 gallon while volume would suggest that it should be stocked ~33% less than the 60 gallon. This is roughly speaking as stocking isn't precisely linear like this.

Personally, I think footprint is a better judge of stocking than volume assuming you have adequate nutrient export. I think a lot of the <75 gallon rimless tanks available have disappointing footprints and I'd like to see more long, shallow tanks than cubes. IM seems like it does a better job of this than other companies.

What do you think?

 

[WalkerLovesTheOcean]

You are exactly right.

As long as you have proper nutrient export and hiding spots for fish to manage aggression, footprint 100% decides how heavily you can stock your tank, and with what fish. I see too many people say "Oh, well I have a 125 gallon tank so I can get a blue tang", when really their tank is only 4 foot long. Then, they say "I've seen tons of people have blue tangs in their 125 gallon tanks", when really those people have 5-6ft 125 gallon tanks, so they are able to keep blue tangs. Volume vs. Footprint make a huge difference in what you can stock your tank with.

 

[edsbeaker]

^ Exactly

I only consider the footprint to judge what fish I can keep. I think volume is useless. For instance my last tank was 75 gallon. Most people would assume it was a 4’ tank, but it was only a 3’ tank. Volume is just too misleading these days considering all the different widths and heights of tanks.
My present tank is 170 gallons, which could be 6’ or even 7’ but is actually only 5’. This makes a huge difference in what fish I can keep,

 

[jabberwock]

I am going to go with footprint. Scape is also a defining factor. If you get the right fish to occupy the various niches of habitat in your tank, then you will have arrived in Elysium.