Solar Powered Rain Barrel Irrigation System

 

We live in Florida, and rain is usually very abundant.  Drainage in our area is excellent.  So even after a heavy rain, it's all gone by the next day, and the sun is once again blazing.  We are fortunate to have a septic system, which makes our cost of water very low.  Typically $35/month, which includes watering the lawn in the dog run area.

Gardens do okay with chlorinated city water, but love rain water.  I bought a Fiskars rain barrel, which is a very nice product.  Over priced, but does what they claim.  Below you will see how I'm currently using this water with my garden, and some of the upgrades I have in work.

 

Last year I bought a Fiscars rain barrel.  Had one at my last house too.  This works extremely well.  The inside is painted black, which prevents algae growth.  This will be the water source for all of the boxes.

Even though the rain barrel is a bit elevated, it lacks enough pressure to effectively push water through a dripper system.  I bought this pump on Amazon for under $30.  Same type you'd find in an RV, or on a weed sprayer.  A timer will be added to automate the system. (likely Arduino based).  I believe all 5 boxes can be watered simultaneously, but I'll test it to find out before burying the plumbing.  At worst, I'll have to perform this in zones.  The downside is a more complicated timer, and the expense of more hardware.

My solar setup at the house is 12V.  It will be easy to supply power for the pump, and a timer.

Unfortunately, my Ace Hardware didn't have a 3/8" barb to 5/8" barb adapter.  Had to buy 3 pieces to accomplish this task.  A standard garden hose is 5/8", and the pump fittings are both 3/8".

This will connect the rain barrel to the pump.

The outlet of the pump is connected to another adapter, allowing it to attach directly to the 3/4" PVC plumbing that will be used to route the water to each box.  Ready for a bench test.

This pump is very quiet, yet moves plenty of water for a dripper irrigation system.  No worries of over pressuring anything.  The pump will shut off at 35 PSI automatically, and the dripper hoses are connected to a pressure reducing manifold.

Hard to hold the camera, and the PVC pieces together (none were glued yet), and take a picture.  There are two holes on opposite sides of the line, every 6 inches.

Update, Feb 7:  Rained all afternoon and evening yesterday.  Finally got a break in the weather today.  Time to get the plumbing done.

12" uprights were added where the plumbing meets the boxes.  The pressure regulators were left off, allowing the air to be purged from the lines.

With nothing connected to an open port on the regulator, you can see how much would flow if the flow wasn't further reduced on the end of each line.

An overview showing the plumbing to all 5 boxes.  A very simple layout. Easy to add or modify later.

As Murphy would have it, the original water valve on the rain barrel split, wasting all the water that was collected yesterday.  Fortunately, I had already ordered a brass valve to replace it.  I did have to open up the hole with a Dremel first.

Had to cheat.  Filled the barrel 1/4 full with city water.

Decided not to use the dripper line I had bought earlier.  Might try it later. 

For 3 of the boxes, I went with a 360 degree sprayer.  The flow is adjustable by simply adjusting the tension on the sprayer head.

The blackberries and pineapples each have their own dedicated drippers.

The gardens are also using the 360 sprayer.  Will likely put in individual drippers later.

Preliminary testing done!

I may still end up using an Arduino board to control the pump.  But for now, I have a more effective solution.  The fenced in dog run next to the garden area already has a sprinkler system using city water.  I added a rain sensor, so it won't water the yard when it's been raining.

For now, I will tie into one of the zones.  It will produce a 24VAC signal, intended to operate a water valve.  I brought a cable to my pump box from the Rainbird sprinkler timer, and converted the 24VAC to 24VDC via a bridge rectifier ($3).  Then connected the output to a 24VDC relay ($3).  This will be the control circuit for the pump.

Inside the box is a sealed lead acid 12VDC 7AH battery.  It can be placed in any position without concern of it leaking.  A cable from the box goes to a 15W solar panel, recharging the battery each day.

I had bought this Carlon box from Home Depot a while ago.  It was intended for another project, but I ended up buying an even larger box for that one.  The pump, battery, relay, and bridge rectifier all fit inside nicely.  It's a weather resistant box, intended for outdoor use.

A closer view of the bridge rectifier and relay.

I carefully measured, then drilled a hole in the back of the box, and front cover, to allow the water lines to enter/exit.

I later replaced the clear tubing with black tubing to prevent algae growth.

Looks like a typical Bosch type automotive relay, but this one is a 24VDC model.

Has a built-in mounting tab, making for easy installation.

The schematic shows how things are connected.  The drawing does not show the master off switch, or the connection to the valve that was later added.  I will update the drawing soon.

Bypass switch installed, and the battery set on its side.

The 15W solar panel is temporarily resting against the fence, and the irrigation pump/control box is setting next to the barrel  This weekend these will get mounted, and the mulch will be put down.

Took the trim cover off the sprinkler controller.  This is inside the dog run area, which already has a sprinkler system.  I connected a wire to zone 4, from the 12V pump control box.  When the dog run sprinkler system kicks on zone 4, it will also operate the garden irrigation setup.

The battery measured 12.7V yesterday, with no charging.  The panel has been charging most of the day.  The max current this panel can supply is about 1 Amp.  Not really enough to damage the SLA 7AH battery, though the float voltage is a bit high.  I later added a small Morningstar charge controller.

With the 12V pump running, and solar panel assisting, the battery voltage dropped a bit.

A filter screen was used at the outlet of the barrel to catch course debris.

After two days, it was already clogged.

Found this filter on Amazon for $7.

Has a much larger surface area, so it'll take longer to clog.  It's easily removed for cleaning.

About a week after installing the filter, I removed it for a visual inspection.  Yuk!  I will soon need to scrub the inside of this rain barrel, but the filter did exactly what it was supposed to do, and water still flowed.

A quick blast from the hose and it's ready to go again.

Installed on the rain barrel, ready to go again.

I had noticed a lot of pollen floating on the surface of the rain barrel after a recent rain.  When the barrel is full, the water is automatically redirected back into the downspout.  The downside is no skimming of floating debris.  I fixed that today with $2 worth of parts.  Two 3/4" electrical conduit fittings, and a rubber washer.  Got all these parts at Ace Hardware.  The outside diameter of the washer is much larger than needed, but that's what they had available.

Simply slips over the threads.

The other end of each fitting will slip fit regular 3/4" PVC.

The entire assembly before installing it in the barrel.

The small dimple above the newly drilled hole is the height of the fill on the other side of the barrel.  I wanted the barrel to continue taking in rain water, and flushing out any floaters with this drain, so the drain was placed slightly lower than the fill tube.

The rubber gasket goes on the inside of the barrel, on the male fitting.

On the outside of the barrel, the female fitting is threaded on hand tight.

Ready to test.

As Murphy would have it, no rain since I put in the IBC tote.  Had to use city water to refill the barrel.

3/4" PVC pipe will be added to direct the overflow away from the house, but this was a quick test.

Hard to capture on a still picture, but it was doing a nice of dumping the floaters.

Ready to add the drain line.

 

The 3/4" PVC drain line was attached.  I will likely spray paint this a color similar to that of the rain barrel.

Update 3/15/16:  Fiscars mounted the valve about a foot from the bottom of the barrel.  I'm guessing that was to allow a watering can to be filled if the barrel was on the ground.  Probably 10 gallons that can't be used.  They have a molded recess that is obviously meant for a valve, but it had no hole.  I bought both of these valves from Amazon.  The upper replaced the original broken plastic valve.  I just drilled a 1 1/4" hole and added the lower valve.  Now I can use more of the collected water.

Since I have the barrel on blocks, it wouldn't be an issue to use the lower valve to fill a watering can, or bucket.

A quick test, all sprinklers are working properly.

Mulching has begun.  A layer of weed cloth is put down first.  Then it's covered by a heavy layer of red cypress mulch.  This was twenty 2 cubic foot bags worth.  On sale at Home Depot for $2.50/bag.  Any grass that sneaks up around the edges will get a shot of Round-Up.

I'll pick up another 10 or so bags tomorrow, hope to get this on done on Monday, which is a Federal Holiday.

Update 2/19/16:  Finished with this stage of the mulch.  I'll put up a decorative border to separate the yard from the garden.

I'm learning that my present rain barrel has enough water to last for about 5 days.  I asked a nearby business about them selling me an IBC tote, and/or some 55 gallon plastic barrels.  These had food grade alum inside, which is water soluble and easy to clean.  They were happy to part with 1 tote, and 9 barrels, for the cost of lunch.

This is one of those days where it's nice to own a truck.  These totes take up the same footprint as a pallet.  The distance between the fender wells is greater than 48", so it easily fit.

Getting it home was easily.  Moving it to the side yard was a bit more difficult.  This weighs about 100 lbs. and is awkward to maneuver.  I was able to fit it on the back of the golf cart, and put a strap across the top to hold it in place.

This area will get weed cloth and mulch too.  The tote will probably be put on a cinder block platform.  It will also be covered to prevent algae growth.  This tote holds 275 gallons, which dwarfs my existing rain barrel.

Update 2/20/16:  I recycled some unused pavers I had stored behind the shed.  Since the yard is graded away from the house, the pavers were stacked 2 high to level the tote.  And since I'm using an electric pump to move the water, no need to put the tote up high to increase the water pressure.

The weed block cloth and mulch should greatly reduce yard maintenance in this area.

The IBC tote was slid into position.

I need to buy more weed block cloth, and another 6 or so bags of mulch to finish this off.  I will also add a decorative border at both ends of the garden to separate it from the yard.

UPDATE 2/28/16:  The IBC tote cover arrived.  It's a sewn nylon material, and fits perfectly.  Sunlight will quickly turn untreated rain water into algae sludge.

A hole was cut into the existing ran gutter.  The fitting was placed underneath to maximize flow.  A heavy bead of silicone sealed it.

More silicone was added to the screws inside the gutter.

There are two existing downspouts on this gutter.  They are on the ends.  I want most of the rain to go into the tote, so a bead of silicone was used to divert water back towards the center of the gutter.  During a torrential downpour, water can still exit through the original two downspouts when the water is deep enough.

The plumbing isn't finalized yet.  I need more 2" fittings and pipe.  Had to use scrap pieces for the moment.  The 3" main downspout is a "first flush system".  Approx 2-3 gallons will first go into this pipe, and a plastic ball will float to seal of the crud that first washes off the roof during a rain.  A tiny drain in the end of the pipe will empty it after the rain has stopped, resetting it for the next storm automatically.

The 12V irrigation pump and controller, will be mounted on the side of the tote.  I used the existing paneling, and added a couple of 1/4-20 stainless bolts.

A quick test fit of the new larger box.  The box I had been using didn't have enough room to orient the pump sideways, allowing the tubing to go through the sides of the box.  This one has plenty of room.

With the plumbing and box removed, the cover can be re-installed, and cuts can be made for the inlet fitting...

... and the two mounting bolts.

With the temporary 2" overflow plumbing put back in place, just in case I get lucky enough for it to rain.

All the components were transferred to the larger enclosure.  The water line was swapped from a clear tube, to a black plastic.  No worries of algae growth now.  Also added a 4.5A Morningstar charge controller.  The switches were not mounted to the cover in this picture.

The water valve arrived from the eBay seller.  It's a 12VDC model, and is tied to the water pump.  Both operate when power is applied via the relay.  I used a temporary connector to verify operation.  Waterproof connectors will be used soon.  It works as expected.  Now water will not flow through the pump when the system is off.  It had been slowly weeping due to the head pressure from the higher rain barrel.  No more wasted water.

Mulch does a nice job of hiding the plumbing, but it's still easy to access if needed.  I'll probably put a cover over the valve to prevent it from being stepped on.

The control/pump box closed up, ready to go.  All the wires will be cleaned up and hidden.  And soon as we get rain, I'll start using the new IBC 275 gallon tote, rather than the 65 gallon Fiscars rain barrel.  Weather guessers are predicting rain next weekend...

The edging arrived.  I bought this via Home Depot online.  Made from recycled tires.  Very heavy stuff!  Each box has four 4' sections, and long plastic spikes to nail it in place.

The wife approves, so this portion complete.

Still need to buy a couple of waterproof switches to replace the ones presently in use, mount the solar panel, and finish the mulch bed.  Almost done. The system is 100% functional at this point.  The garden is growing, and the watering system operates 10 minutes every morning, unless there's been significant rain.  It will skip watering that day if the rain sensor on the Rainbird sprinkler timer is still wet.  I can also run it anytime by flipping the bypass switch.
 

A short video showing the system in action.

 

 

 

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Last updated 03/16/16    All rights reserved.