Hi there thanks for any input. I have a mature reef (fish, invertebrate and soft coral) aquarium running for over 6 years now. It is a Juwel Rio 180l with the Juwel internal filter and Juwel internal marine skimmer. All bought new but the skimmer it seems has had its day. Problem is the skimmer is constantly overflowing with tank water and spilling onto the floor. I have the air intake set next to zero but even so often the skimmer will overflow with tank water, spill onto the lid and then on to the floor. This may happen only once every few months or a few nights in any given week there seems to be no predicting or preventing it. This was a nuisance previously but with an eight month old in the house having to constantly clean up water and being constantly aware of dirty tank water on the floor with baby toys etc it is just unmanageable. So much so that the skimmer has been turned off for about three months now (cue algae bloom and dirty tank). My wife and I have seriously considered getting rid of the whole set-up (we currently have laminate floor - which is bad when it leaks - but are having some work done which will include carpeting the floor where the tank sits - which would be terrible). In an ideal world I would love a new sumped system but this is off the cards. I am considering replacing the internal with an external hang on skimmer (Skimz SH2 model) as I found a really good price from my lfs today. I've tried to find some online reviews or videos and just wondered on anyone's experiences of hang on skimmers in general or the SH2 in particular. I think this could be a good compromise as its much cheaper than adding a whole sump system (new cabinet, sump tank, new skimmer anyway etc). The SH2 is a skimmer within an acrylic vessel which sits on the side of the tank. My reasoning is if the same problem occurs and excess tank water fills the skimmer cup will overflow into the acrylic vessel rather than the top of the tan and then down and then onto the floor - is this correct or am I likely to have the same problem? Obviously I empty the skimmer regularly of gunk but in case the same water overflow occurred). The reviews I have managed to find suggest that the Skimz range of skimmers are also very quiet (a big plus on the Juwel internal simmer which is very noisy and often fills the aquarium with micro bubbles). Can anyone offer any advice either way? Thanks.