Table of contents for Rain water collection
We know that we promised to come back to the rain water collection system after we had a chance to test it out. Well, it was a nice day and we definitely had some improvements in mind for this system. The first rain water collection system has been up and running for about 3 months. So your wondering why we are switching form the aeroponics system to the rain water right now. This is because in order to grow the plants, we need a reliable source of water. The 65 gal barrel just wasn’t enough capacity during storms, thus the expansion.
Here’s a rough break down of what we did to the system:
- Painted all the barrels mat black to keep out the sunlight and cut down on alge growth.
- Added two more 65 gallon barrels to the system for a total of 195 gallons of bad-ass rain collection capacity.
- Hooked all three barrels together with 1″ double barbed adapters and vinyl tubing.
- Made a new sand filter with much increased surface area to improve the flow rate.
These changes essentially remade our collection system. The only part of the system we didn’t change anything about was the first-flush component. This wasn’t because it worked flawlessly, quite the opposite actually, but because we haven’t figured out how to fix it yet. If any of you know good way to build a first-flush that alleviates the clogging problem we have been having, let us know.
Here’s how our system looked before we started:
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Barrel Painting
We painted all of our barrels black so that we could reduce the growth of algae and therefore reduce clogging in the mechanical filter of the RO system. We had read that you needed sun-cover before but we hadn’t put any sun protection in our system due to youth and exuberance. We didn’t know if our system would be growing much algae due to the sand filter taking out majority of the particles, but it still acquired algae growth.
A quick trip to Home Depot, not the cheapest place for paint, scored us one gallon of matt black outdoor paint. Of another note, it would be best to roughen the sides of the barrels before applying the paint to them. It is hard to get any kind of paint to stick to the HDPE plastic that they are made out of. We, of course, learned this after we had already painted the barrels 
Below are some images of the painting procedure. We actually had to put three layers of paint to make the barrels completely opaqu.
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Barrel Additions
We added two new barrels to the one barrel already in the system to boost our collection capacity up to 195 gallons. This gives us some serious water collection ability, especially once we get the clean water barrel installed in the house.
Barrel Piping
We wanted all our barrels to be included in the collection system so we hooked them together with 1″ barbed adapters and vinyl tubing. This seems to us to be a good solution because we have seen others do it with some success and it was just easy to install. Tools required were a 7/8″ spade drill bit, a dead-blow hammer, and a drywall knife.
At first, we thought we were going to require the assistance of our muscle-bound friend Eric for this job. After a bit of consideration, we thought a dead-blow hammer could probably replace him…we were right! A dead blow hammer is a quick substitute when you don’t have an Eric at hand!
You will also notice that we added overflow spouts on the top of the barrels that point away from the house. These are obviously for in the even that the barrels overflow.
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New Sand Filter
Our old sand filter left much to be desired. Namely, it would drain too slowly and be swamped by the incoming water off our roof. This was non-optimal as the bucket would then overflow carrying sand with it into the top of our unsealed rainwater barrel. We could have mitigated this by sealing the top of the rainwater barrel but we opted to just fix the problem at it’s source instead. This will result in more water being caught by the system anyway.
Our new idea was to take the top half of another fifty-five gallon plastic barrel and place it on top of the collection barrel, bunghole to bunghole. The bottom would be cut off and we would have our filter-cloth-gravel-sand filter inside just like our bucket. The big difference is that this filter has much more surface area, decreased depth of filter media, and increased outflow surface area and thus much more flow. Add to this the increased height of filter wall, 18 inches, above the sand level to store excess water and you get considerable pressure working to push the water through the sand filter even faster.
To link the two barrel tops we used 2″ black ABS pipe. This size pipe fits very snugly down through the bung holes and effectively routes the water where we want it. This also locks the two barrel tops together so that there is really no chance of the sand filter being knocked off the rain barrel unless the whole unit tips over.
That rock in the final picture is to counter a problem we noticed in our original version. The water would tend to dig holes in the sand–down to the rocks if we let it–and this would undermine our filtering action. To counter this we put a large flat rock directly under the path of the downspout. We think it will work well but only time… Sorry, but we got so excited that the sand filter was finished that we totally forgot to get a pic of the finished system. But it looks like pictures 8 and 9 below.
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Next Time
We will be working on the inside water barrel so that we can hook the RO system up permanently. Once that is done, our collection/filtration system will be complete. That leaves us with a lot of clean water to use for our aeroponics system and our fish.
That’s it for this time. Be safe and sustainable!
P&S
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