I am about to start on my dual IBC tank rain harvesting system. I wondered if anyone else has constructed this type of system and has any tips? I already have a 900ltr tank behind the garage which was left by the previous owners. The garden sprinkler pumped system can empty most of that in about 20-25 minutes. My main concern at the moment is diversion of the rain water from the gutters as i don't think a bog standard diverter will be man enough to harvest and replenish 2000l unless it is over months!? (rain dependant obviously)