Is it allowable to claim coffee, tea and filtered water for business purposes in a private company?

To what extent can one deduct coffee, tea and filtered water for business purposes (operating as a private company)? I am fully aware that input tax cannot be claimed on these expenses. Will one however be able to deduct for income tax purposes under Section 11(a) if the purpose of buying the coffee, tea and water is to consume during business hours?

Yes, if this is a normal office expense then this will be allowed as a deduction against income earned.