To size the water tank you don't need to do have a exact hydraulic calculation which normally come from contractor side If you are working for consultancy.
Once you have pump size then you can size your tank based on the time duration required to supply the water.
For example
If you're pump...
Is it required to provide the sprinkler above the GRP water tank?
In NFPA13 there is nothing mentioned about it and I don't believe it is required .
Can someone input your valuable comments with related code reference ?
I thank you very much for your replies .Can someone please give me reference with section of code .I have checked in the ASHRAE62.1 but could not find exactly .
