I've got one of the PFK cubes in my living room that I've always had problems with really. It sort of splutters from one kind of ugly mess to another! Anyway start of the summer holidays I decided to re-scape it and then start EI on this tank (as I just about have the time to keep up with 50% water changes on a 25l tank!). The result of doing this was an explosion of algae. Some had always been in the tank. The BGA started to decline and the little bits of BBA are still there (but not getting any worse), but these minor problems were replaced by huge amounts of a filamentous mass of green algae. Long strings of it were hanging and standing up in the water as it pearled! 3 days after adding 6 Otos to the tank it has almost all gone! They have ate and ate and ate until their bellies are so rounded that they look like they might burst! I've always loved Otos but never appreciated that when there's lots of algae, just how much they can pack away in a short space of time! In another couple of weeks the Marsilea and E.tennellus 'lawns' may even have filled in enough to warrant a picture. The only problem... The algae has been replaced by lots and lots of Oto s***! They make my SAEs in another tank look very lazy!