The past week has been quite rainy. Since the night temperatures have only been getting down to 36 degrees or higher, I decided to hook the rain barrel system up.
I went to work on Thursday and it started raining mid-day. By the time I got home, I checked on the barrels and they were already completely full! That was approximately 220 gallons of water already stored and ready for use. The funny thing is – we only had about a quarter of an inch of rain during that time period – and I managed to get 220 gallons from that off of a 24 x 24 garage roof (about 576 square feet).
Friday I went out to harvest some of that rain water to fill up some gallon jugs. I've been using rain water to water the seedlings inside instead of using tap water from the house. When I went out there, I decided to test the water timers to see how well they do in a low pressure situation. While I don't know how much water pressure I have, there is a decent amount since the barrels are all hooked up with 2" PVC pipe about five feet in the air.
Without the water timers hooked up, I was able to fill a gallon milk jug in about 10 seconds or less – pretty amazing. That is coming out of a 1/2-inch PVC pipe.
Then I hooked each of the timers up. I don't have statistics right now for how quickly they would fill up a gallon jug, but I will do that at another time.
The first one I bought is a timer that does everything for you. You set the time and then there are several options. It is a Nelson automatic water timer. You can set it to water everyday for 15, 30, or 60 minutes. You can also set it to water every other day for 15, 30, or 60 minutes. Lastly, it then allows you to twice every day for 15, 30, or 60 minutes. I've always used the every other day for 15 minute setting.
I hooked the timer to the male threaded PVC adapter (where I can hook a hose too) and turned this thing to the On position. Within a few seconds, water started trickling out – not very good. This timer requires a decent amount of pressure to get water through. I estimate that the throughput on the timer was about 1/4 what the throughput was without the timer hooked up.
The next water timer is a manual water timer – a Gilmour timer. You have to set this one yourself whenever you want to water – but it will just automatically turn off when the time is up. You can set it anywhere from just a few minutes to 120 minutes.
I hooked this one to the PVC adapter and turned this one to the Manual On position. Same thing as the Nelson timer. The flow was maybe 1/4 of the flow that the 1/2-inch PVC pipe would push out without obstructions.
So, I'm not sure what to do yet about the watering situation with the garden. I have heard of low pressure water timers, but I'm reluctant to buy one online and find out that it has the same problem.
What I don't understand about these timers is this – why can't someone just invent a timer that turns a ball valve to open the flow of water? It seems all of these timers have obstructions or something that cause them to seriously slow down the water flow – but why not make a timer that allows a full-flow of water to go through? Standard PVC ball valves work just fine – which is what I use on the spigot connection to turn on and off the water flow.
Anyways – moving on.
So today I got some motivation and decided that it was time to upgrade the water system since it fills quickly. I figured that when I first made the system I would upgrade in the future. I want to ensure that I have enough water stored if we have a few weeks without much rain.
I made a trip to the place where I get the barrels and picked two up. I got home and drilled a hole in the bottom (well, it really will be the top of the barrel – but the opposite side of where the two bung holes are). I then put some patio screening over it and used some super glue to put it in place. This will allow air pressure to leave the barrels as they fill up – and the screening will keep the mosquitoes out.
I then had to go and get two 2" PVC unions, two 2" PVC T connectors, two 2" PVC male threaded connectors, and another section of 5-feet of 2" PVC pipe. The PVC unions were about $7.68 each, the T connectors $2.09 each, and the male threaded connectors $1.02 each. The 5-feet of PVC pipe was then $3.17 for it. So, everything I needed to make two more rain barrels for $24.75. Not bad – basically $12.38 per rain barrel. However, I had another dilemma – since these are in the air, I needed building material. Woops – there was another $20. I had to get two 12-foot length 2×6 treated boards and two 8-foot 2×4 treated boards. The 2×4 were the posts and the 12-foot length of 2×6 was used so all the rain barrels will sit on them. Previously I had a 8-foot length 2×8 – but a 2×8 was a bit overengineered for this. Each barrel takes up about two feet of space – so plan accordingly. I then have the vertical posts placed four feet away from each other.
Just my luck – it started raining during the process. I got the two holes dug for the posts and started drilling the holes in the 2×6 boards to put the lug screws through. It got muddy quickly since this is build on a hill beside the garage. But, I managed to get it all done.
So, now it is an approximately 330 gallon rain barrel system – up from the 220 gallon rain barrel system. I think I'm satisfied with this and I'm done building it.
While there is the advantage of additional storage capacity, I also tweaked the downspout a bit. Previously, I had a 90-degree gutter elbow and then a straight piece of downspout attached to it that was about six inches long. Well, where the elbow and the straight piece come together, there was a leak and it made ruts in the ground. So, I moved the whole rain barrel system over closer to the downspout by about eight inches – so I no longer needed the straight piece; the 90-degree elbow attaches directly to the hole in the gutters and diverts it right into the barrel now.
In the picture below, you can see on the upper left side of the white rain barrel, there is a 90-degree elbow that was cut down to size connected to the gutters.
Below is the under side of all the barrels. Again, they are all hooked in series using 2" PVC pipe with a PVC union between them so I can disconnect the barrels individually.
And lastly, you can see the main downspout attached to the garage. It is not attached to the gutters though (hard to tell in the picture below). Then there is another downspout coming from the top of the white barrel – this is the overflow downspout. When all the barrels get full, water will overflow into this and go down this to the ground.
March 14 Update – More Concrete Timer Trials
This afternoon I got out and did some better testing of the water timers.
After I got the new system hooked up, the barrels collected just about 28 gallons of water amongst all six of them. On the white barrel, there are lines every 10 gallons of capacity. Of course, since the barrels turned upside down, the numbers also go backwards – so 50 gallons shows at the bottom. Anyways, the white barrel was filled up to almost 3/4 to the line of the 50 gallon mark. Also note that the white barrel is also approximately two inches higher than the rest of the barrels – so I estimate that all five barrels have 4.75 gallons of water and the white barrel has about 4 gallons of water (total of 27.75 gallons).
Since the barrels are not completely full, this means there will be less pressure as well. When the barrels get full, I will take measurements again.
Using just the ball valve to open the flow of water to a gallon jug, the time it took to fill was just under 8 seconds. This yields about 7.5 gallons per minute. While I can't be certain as of yet, I don't expect this to decrease with the barrels completely filled – maybe by one second at the most. The flow was fully unobstructed so this is what the 1/2-inch PVC pipe is capable of.
I then dumped the gallon of water back into the top of the barrel – just to ensure that the numbers would be fully the same.
Next up – the Gilmour water time. I was very unimpressed and know that this clearly will not work in a situation where the barrels are at this level. The Gilmour manual water timer took 68 seconds to fill a gallon jug – that is 8.5 times slower than just using the unobstructed ball valve on the PVC pipe. Therefore, the Gilmour manual water timer puts out about 0.88 gallons per minute.
Water was them dumped back into the top of the barrel.
Lastly, the Nelson automatic water timer. The Nelson water timer was quicker than the Gilmour – with it taking 40 seconds to fill up the gallon jug. The Nelson timer effectively worked at 1.5 gallons per minute in a low pressure situation. Therefore, my original estimate of the timer output of 1/4 compared to the unobstructed flow was almost correct – the actual output was 5 times slower, or 1/5 the output of the unobstructed flow.
The Nelson water timer may work fine for the garden – but that means I need to buy three more timers! I need four total – because I'll have behind the garage, next to the house, and two 4 x 20 areas up front – and they will all have to be setup so that one waters an area and shuts off – then the next one would water the area and shut off, etc. With the timer being on for 15 minutes, this would put out 22.5 gallons of water for each water space – multiplied by four watering spaces is 90 gallons of water. Wow – good thing I upgraded the system to 330 gallons – because it would only take 3 2/3 waterings to fully drain the barrels! That means I have a capacity of just about one week of water if I water every other day – provided there is no rainfall in the week.
How did you link the barrels together side-by-side on the top to fill the water into each as it rained? Also do the lids come off? Do you have a photo of the mosquito screen somewhere or more photos of this system?
The rain barrels are connected together by 2″ PVC pipe underneath the barrels – there isn’t anything connecting them at the top.
The mosquito cover is just made out of fine aluminum mesh – like patio screening. You can use anything with this fine of a mesh to cover the air holes in all of the barrels.
The first barrel that accepts the water from the downspout has a air conditioner filter to keep out all of the debris from the water coming in.
Since the 2″ PVC pipe that connects all of the barrels together is under the barrels, the water comes in the first barrel from the downspout and starts to fill up. Because water finds its own level, the water fills up all of the other barrels hooked in sequence at the same time.
low pressure timers
I also tried to connect a timer to a water barrel with very poor results – just a trickle coming out. I have done some research and drip workds supposedly has one that should work:
http://www.dripworksusa.com/store/btimers.php#TLP
I will try it and let you know!!
Re: low pressure timers
Hi John –
I got another timer over a month ago that is basically two units – one is where you can put the hose and it has a ball valve. The other part is the electronics – and it sits right on top of the ball valve – and opens/closes the ball valve. I’ve found the water goes through this with ease and takes care of the problem.
However, I am just manually opening the PVC ball valves I put on all of the outlets right now – I don’t have the water run for more than five minutes because that is all the plants really need. The timers have a minimum run time of 15 minutes – which is just too much.
So all this talk about water timers, and I’ve stuck with the manual watering method.
Hi John,
I read your blog about your rainwater harvesting system and the issues you are or were having with the timers. Maybe you have figured this out by now. The timed valves you are using require a minimum pressure to operate and even then they may not work well. The reason for this is that they are diaphragm valves. This type of valve costs little to produce and has many non-critical applications for it. What you need to use is an electrically or pneumatically acutated ball valve or gate valve (anything else but diaphragm. Unfortunately these things are expensive $80+. I’ve been trying to find some my self and even the plumbing stores here in town don’t know of anything less expensive. Hope this helps, Tom.
Thank you for your comment, Tom.
I have indeed figured that out and purchased a ball valve water timer; it is a Gilmour timer. I purchased it for about $30 at the local home improvement store. I actually do not even use a timer because the minimum value on the timers are 15 minutes. I only need to let the water run for five minutes for each gardening location. 15 minutes is too much and would use a large amount of water.
Hi Brian,
Are using a drip system from this in raised beds or beds on the ground? I have eight barrels and was planning on doing drip irrigation from them w/o high pressure in my raised beds. I’m still in the planning and research stage. I may not have my barrels high enough.
Thanks, chuck
Hi Chuck –
The irrigation system I’m using is all above ground using 1/2-inch PVC pipe. I have 1/16-inch holes drilled into the PVC pipe where each plant is to minimize water usage and to deliver water right where it is needed.
Rain barrels will not give you a lot of pressure unless you add a pump to it or raise them as high as you can. That is why I have mine directly under the gutter; basically getting them as high as possible – since I don’t want to use a pump. The water pressure still isn’t enough to even push through a soaker hose – so I opted to use the PVC pipe which is less than $1 for a 10-foot section.