Thay have a bad press
Mine works real well now but I have had the following problems:
1. leak from the inlet pipe where the o-ring meets the body seems to come back every time it is broken down for cleaning and goes after a few days/hours
2. constant (2-3 times aday) adjustment of the flow to maximise the skimmate production
3. alittle noisy
4. very sensitive to changes in water quality, density, salinity, again requires adjustment.
I would not buy one if I had the choice again but I does work really well now but I rally had to stick with it and not let it beat me. V dissapointing its sold as an entry level skimmer as it requires some skill and alot of patience to get it to work.
Oh and dont get one without the surface skimmer as they are even worse!!