So I've decided to try something different and swop out my usual tropical fish for a few goldfish - 3 comet goldfish to be precise. I'm using my current Jebo R338 setup, minus the heater and I've added an air pump with an airstone for a nice bubble effect. I haven't needed to modify anything else and the new goldfish seem to manage just fine with the current created by the powerhead.
The Jebo R338 actually makes for a superb, low maintenance goldfish setup. I'm really enjoying the brilliant (goldy) red of the comet goldfish and they have more presence than tropical fish I have had in this tank before. They are also very active little chaps, so a lot of fun to watch!