The system did well for most of the 2nd year -- it collected and distributed water well.
But, we did have a freeze up of water in large pipe that acts as a first flow diverter ton the system -- details below.
In the fall shutdown, I took the plugs out of the out of the short pipes at the end of each of the two collection gutters so that any water collected in the gutters during the winter would drain to the ground and not go into the system. And, I opened the valve at the end of the first flush reservoir.
Apparently the valve on at the bottom of the first flush reservoir got plugged at some point and water accumulated in it. The water froze and broke up the reservoir PVC pipe pretty thoroughly. This was probably aggravated by the fact the the reservoir pipe is larger in diameter than the collection pipes it attaches to, so the ice had something push against as it expanded during the freeze up.
During the water collection season, the first flow diverter is normally empty, and when a rain starts, the first few gallons of rain water that might have more junk and contamination go into it rather than into the tank. Once the diverter fills up, the full rainwater flow goes into the tank. I usually leave the valve on the bottom of the first flow reservoir just slightly open, so that after a rain it slowly drains out and is ready for the next rain. For the winter, I open the valve all the way. My first flow diverter is smaller than most of the references recommend, but we don't have any nearby trees and the stub pipes on each gutter pick up the mineral grains that come off the asphalt shingles.
For now, I just took the first flush reservoir off where it is threaded into the collection piping, and put a threaded plug in in place of the reservoir. So, the system is collecting again, but with no first flush reservoir.
I'm debating about how to replace the first flush reservoir in a way that will lessen the chance of freeze damage.
Other than the freeze damage, the system performed well through its 2nd year. It collected water well and filled up the tank.
I had a little trouble with the inexpensive Harbor Freight pump impeller seizing up, but managed to free up the impeller and a little sanding and some oil put it back in order. For the most part, we could probably just use gravity feed.
I did leave the tank about 1/4 full through the winter. I thought that in the open and somewhat flexible tank that there would not be a problem if the water froze, and there was no problem. I'm going to do the same this winter and keep a closer eye on whether is freezes solid or not. The tank does get sun on the south side, and the dark green absorbs the sun well, so some heat gets transferred to the tank.
The reason for not draining the water completely from the tank is to have some extra water on hand in case of long power outages in which our well pump would not be operational.
Gary March 26, 2013