yep. to have it totally open with the level of the water at the lowest you line up the two dots. Then you adjust from there. I found matching the dot up to the printing part of the tube gives me the best water height in the skimmer. How long have you had the skimmer btw? It took almost 2 weeks for my eshopps to break in fully so that might be a consideration.
180g Reef - 60g Rimless Reef -90G FOWLR- 125g Malawi Cichlids- 40b REEF- 34g Fresh Planted-working on- 20L FOWLR- working on
I have a mix of many different saltwater fish amongst my tanks, but I love my Tangs most of all.