About a year ago got my back up water system up and running like I wanted it. I have good water from the well but it is limited it runs out quick. This was going to be for back up only. But it worked so well that It's about all we use for water in the house. I used surflo on demand RV pumps. I tied this into my existing pluming and made use of the accumulator tank. I get about 9 gallons of water before the pump kicks on. It runs off the 12 volt batteries used my solar system. No grid needed. That hose you see running up the first tank is clear hose (sight glass) I'm running two surflo RV water pumps.,, I ended up only running one at a time it's all I need having two really doesn't help that much. Other than quicker recovery When I turn on the rain water valve it comes out the green hose until I turn the valve for the tank to receive the water that way I can take a sample of what I'm getting before it goes in my tank. To make sure the nasties are all washed off the roof. I have never needed to use this so far but I have tested it and it seems to work as planed. The water goes into the first tank then through the filters and into the second tank then through the pump and into the house pluming. If you look real close you can see a drain valve on the bottom of the first tank. I figure that if I get any sediment or anything nasty in the bottom of the first tank I can flush it out there. It's 3/4" big enough for that If you look you can see a switch and a small green light. The light comes on when the system is "ON" I'm going to install a small light upstairs that comes on when the pump is running. Just to help keep an eye on things I have few different ways I can fill it I can use my truck and tote and fill it with city water I installed an out side filling tube or I can fill it a little at a time from the well I have now I have spring that I can fill it from or as a last resort I can catch rain water Next I would like to install a propane tank less water heater I'm thinking that when the grid goes down having running water hot and cold and electricity for lights and radio that it would be a big convenience. Yea,, Hot shower with no grid.