| Thats stupid.
Where is this source of crappy information you have come across.
If it is a person then I suggest you change subject matter when you talk to them.
If your diamond is eating well then it will outgrow the 2 foot tank when it is around 12 months old.
1200x1200x600 would be a good size enclosure for it ultimatley.
I had my 7ft long Atherton girl in an enclosure this size and it worked well. | 
