I drip acclimate absolutely everything. Don't think there's ever too long a period to drip something - as long as you keep the container water at the same temp. I have a very small heater just for acclimation. When I know something is going to take a while - I add some water to a larger container, get the heater going in that water, then empty the newcomer in a smaller container within the larger one to acclimate. Once I'm certain the inner container has been overrun by my tank water and then some I check the temp - if all is good - I net it in. If the temp is not quite right I'll float it in that small container for just a few more mins then net it in. I never ever mix my water. Since I can't QT - this is the safest I can get. Sometimes is only for 30mins, other times I'll allow 2-3hrs. Again just depends what it is and their sensitivity level. I believe sea hares are pretty sensitive....
