When talking tank size for a silver arowana the surface area is move important than volume, because the Aro mostly swims at the top 6-8" of the tank. I would still say 18" is minimum depth though. The following is based on the surface area (foot print) of the tank.
In my opinion a 240g 96" x 24" is the minimum for a life take and this would be for a 36" aro. based on that here is the ratio
Length x width divided by 64 = length of the aro
64 is the number of square inches per in of fish
So as follows;
240g 96" x 24" = 2304/64 = 36" aro
180g 72" x 24" = 1728/64 = 27" aro
125g 72" x 18" = 1296/64 = 20" aro
100g 60" x 18" = 1080/64 = 17" aro
75g 48" x 18" = 864/64 = 13.5' aro
55g 48" x 12" = 576/64 = 9" aro
you get the idea, use this ratio for any size tank
Oh and for that 4 foot aro, the ratio works out to be a small lake
In my opinion a 240g 96" x 24" is the minimum for a life take and this would be for a 36" aro. based on that here is the ratio
Length x width divided by 64 = length of the aro
64 is the number of square inches per in of fish
So as follows;
240g 96" x 24" = 2304/64 = 36" aro
180g 72" x 24" = 1728/64 = 27" aro
125g 72" x 18" = 1296/64 = 20" aro
100g 60" x 18" = 1080/64 = 17" aro
75g 48" x 18" = 864/64 = 13.5' aro
55g 48" x 12" = 576/64 = 9" aro
you get the idea, use this ratio for any size tank
Oh and for that 4 foot aro, the ratio works out to be a small lake

, and besides no math calculations is nessesary to give this fish a right size home, this sounds like the 1'' of fish per gallon rule



