just a note on the skimmate again....it's okay if the volume is less, but
IMO it's better to go with a darker, richer skimmate. It means the bubbles have had time to work on the water that's in the
skimmer column and are hopefully able to pull out even more concentrated protein. People vary between a "wet" and a "dry" skimmate, but for your size tank...75ml is quite a bit for one day....it wouldn't hurt at all to lower the volume, but increase the density.
On a side note...I don't have any experience with hang-on-back
skimmers, but if you could find one that takes water from the surface of the water, then you might find better performance for the
skimmer.
By the way...how are your
nitrate/phosphate parameters?
