How many treasure habitats for maximum abundant essence?

How many treasure habitats do you need in a park for maximum abundant essence collection? I always tap those first each day since they give twice the amount of essence.
I currently have 45 total habitats: 19 giant, 10 large and 16 regular. I do not exhaust the abundant essence with the 45 habitats, and now that I can have more habitats at. Level 190 I’m wondering how many to buy.

Also, just a curiosity - When I tap on treasure habitats in rapid succession, I don’t receive essence from each habitat, i might get essence from 3-4 and then it will give me one or two with only DC. If I wait for the smaller treasure habitats to fill up and go back and tap again, sometimes I get more.