If you don't already have a flat/level and secure foundation for your water tank, your local builder will be able to build a sand pad for you.
Problems that are common with other types of water tanks such as soil-side corrosion and fragility are not an issue when it comes to installing Coerco poly water tanks. Thus, installation is much simpler.
If you already have a flat area where the tank is supposed to go, then there is no need for a sand pad. On the other hand, if you don't have a suitable space, then the local builder will be able to build it for you.
It must be noted, however, that most local councils don't require a building permit to install a rainwater tank. Which means that if you - or anyone you know - have the skill set, equipment and competence, then this is something that can be done without a qualified builder.
Remember that in order for your water tank to get the maximum amount of rain water that it's capable of storing, the foundation must be level, stable, and free of debris like large rocks and sticks.
See more on tank pad preparation here:
What type of base do I need for my water tank?