Hey thank you for the donation! We had a minimum in the past and decided to not set a minimum. If a delegator does not have much HP but want to show the appreciation they can delegate what they can and still earn 0.001hive as a think you and ecouragement to raise it over time. Also it would be hard to estimate and communicate what "the minimum" is because it will change related to the incoming delegations. The dust is important for the people who does not have much HP - that's why the minimum is not a thing anymore :) It's not the small delegations that let us struggle - it is the big ones :P