A 180 gallon - may work for juvenile Bamboos, eppies or Coral Catsharks - but not for their entire lives. What size tank/pond you will need to keep any shark for it's entire life depends on the species you choose.
For example - Coral cats, or a small eppie or Bamboo (30" or less) would need a tank of at 480 gallons.
Larger species of bamboos, eppies & Horns (which are at least 3' long) need a tank or pond over 1,000 gallons.
The smallest swimming sharks available to private aquarists - tend to be Smoothhounds which are about 3-4', and require a pond of at least 4,000 gallons to keep for life.
The smallest requiem sharks tend to be about 3.5-5' long, and require a pond of at least 14,000-15,000 gallons.
As for the Nurse Shark - to keep one for life - plan on pond of at least 20,000+ gallons.
A Whale Shark - think at least a couple million gallons.
For those whom are relatively new to keeping sharks - it's best to stick with the Bamboos, eppies, & coral catsharks.
For example - Coral cats, or a small eppie or Bamboo (30" or less) would need a tank of at 480 gallons.
Larger species of bamboos, eppies & Horns (which are at least 3' long) need a tank or pond over 1,000 gallons.
The smallest swimming sharks available to private aquarists - tend to be Smoothhounds which are about 3-4', and require a pond of at least 4,000 gallons to keep for life.
The smallest requiem sharks tend to be about 3.5-5' long, and require a pond of at least 14,000-15,000 gallons.
As for the Nurse Shark - to keep one for life - plan on pond of at least 20,000+ gallons.
A Whale Shark - think at least a couple million gallons.
For those whom are relatively new to keeping sharks - it's best to stick with the Bamboos, eppies, & coral catsharks.