How can I get my horse to jump in an arena?

I've recently started jumping a 3 year old and he has an amazing jump however he can only jump on grass, not sand. He is made for jumping and recently cleared a 5-bar gate to see his friend. Please let me know what I can do to help him jump on sand aswell as he does on grass. Thanks x

What is a VPN?

VPN is (Virtual Private Network) were first used by companies to enable their employees to securely access internal systems such as email remotely (e.g. from home or while on business trips). Today they are increasingly being used for personal use by individuals to protect their privacy while online in public places (e.g. when using the wi-fi connection in a cafe) or in a country where the internet is censored / blocked (e.g. China, Saudi Arabia…).