The Trickle algorithm is one of the main components of the IPv6 Routing Protocol for Low Power and Lossy Networks (RPL). Trickle is used to maintain and to control messages in the network. However, this algorithm has some limitations in terms of power consumption, overhead, and convergence time. In this paper, we present a new improvement of the Standard Trickle algorithm, named Flexible Trickle Algorithm (FL-Trickle). Based on the T time parameters and the Minimum Interval values, the new trickle allows reducing the delay needed to transmit control messages as well as the transmission rate. A comparison has been made between the FL-Trickle, the standard Trickle and the Trickle-Plus algorithms. Simulation results show that our proposed approach outperforms both the standard trickle and the Trickle-Plus in terms of convergence time, overhead and energy consumption. FL-Trickle increases the convergence time by up 58%, reduces the overhead by up to 69% and the energy consumption by up to 62%.