Is it okay to house my tegu substrate is sand?

The sand is fill with calcium and I dont feed my tegu in the sand. I feed it out side the cage.

i wouldn't recommend it honestly i would go with maybe repti - bark or somthing like that

me

You shouldn't because it clumps when wet. There are other problems with it I won't go into.
You can try the following though, they are much safer for your friend:
- Reptile Cypress mulch

- Reptile Orchid bark

- Reptile Eucalyptus mulch - it is environment-friendly and repels
pests, like ticks.

what is that?