function calcMaxDeposit() public view returns (uint) {

        if (totalInvested <= 100 ether) {
            return 2.5 ether;
        } else if (totalInvested <= 250 ether) {
            return 5 ether;
        } else if (totalInvested <= 500 ether) {
            return 10 ether;
        } else if (totalInvested <= 1000 ether) {
            return 15 ether;
        } else {
            return 20 ether;
        }

    }