Monday, May 28, 2012

Setting up a galvanized stock tank as a rain barrel

Though I've written about setting up galvanized stock tanks as rain catchment before, I've refined my techniques somewhat since then, so I thought I'd do an update post on the topic, with particular attention to things I've tweaked. I'll link to my earlier posts at the bottom, which show some additional detail on construction.

First, I used to think it would be nice to have a lot of catchment in one place, with either one large cistern that could hold a 1000 gallons, or a row of tanks. And indeed I've even had a couple of largish tanks linked together in places. What I've found, though, is that I prefer to have single tanks set up strategically at each corner of the house, as it makes delivering the water to the garden an easier task. Also, the tanks are not huge (two 50 gallon and two 100 gallon), but I have found that they are sufficient for supplemental watering. My goal is to have the landscaping part of the garden need only occasional watering during extreme drought. I'm hoping that the rainwater I collect and store will be enough to allow me to go completely off the city water grid in the next couple of years (for the purposes of landscaping or gardening). In other words, I am planting things I expect to survive under desert conditions, and as such, any irrigation that might occur would merely be a friendly boost.

Here is my set up at present:

Two in the front, where they blend in nicely with the landscape:


And two in the back (though I'm only showing one here, as the other was temporarily decommissioned in order to install some siding, and I haven't gotten it back on line yet):
The set up above is one I just re-installed. It too was temporarily decommissioned so that some siding could be attached, and I took the opportunity to clean and refurbish it. It will be used to irrigate an espaliered fig tree that I will be planting to the left. This tank is the first I ever set up, some dozen or so years ago, and since then, I've refined my technique quite a bit. So I'll use the new install as a quick primer on setting up a galvanized tank for collecting and storing rainwater.

First, I elevate the tank, to make it easier to attach hoses and fill watering cans:
Second, I make a cedar lid, which I paint with a weatherproofing stain to make it last longer and look nicer. I've found that though I like the weathered look of cedar on a fence or bench, for some reason it looks like trashy junk on a rain barrel.

I wait until the gutter guy installs the downspout and I can see exactly where the opening will be, then I cut a hole in the top and attach a gutter splash guard. You can find these at the hardware store in the rain gutter supply section:

I then attach mosquito screen attached to the underside of the lid. I staple the screen about two inches from the edge, so that when the lid sits on the top of the tank, it drapes over and creates a seal:

If the lid is going on one of the larger tanks, I make a hinged section, as demonstrated below by my neighbor Karen. This makes it easier to check the quality or level of the water, perform any needed maintenance, or fill a watering can.


I attach a no-kink hose bib to a three-inch long, 3/4" galvanized pipe. Some tanks come with a 3/4" threaded opening, and others do not. If it does not, the pipe can be installed by using thin nuts, as seen in these two photos:

The interior nut also has a rubber gasket to prevent leakage. I put it on the inside, where it seems to last longer than one used on the outside, exposed to sunlight.

I cut an opening for an overflow tube using a step unibit, which can be found on Amazon for a very reasonable price.

At your local Bog Box Hardware, you can find swankier versions of these in the electrical contractor section of the hardware store, where they are usually kept under lock and key to imply that you need to pay an arm and leg for them. Don't ask me how I know this.

You might as well order one now from Amazon so that it will be ready for you to use on your new tank. Go ahead, I'll wait.

The overflow tube is a flexible tubing also found in the electrical section. It has two threaded ends, and comes with gaskets, nuts, and couplings that screw on. These make it easy both to attach the tube to the tank, and then a hose to the tubing:

Though the nut makes the coupling is unnecessary to attach the tubing, the coupling comes in handy for another reason, since I can cut a small piece of screen and place it inside it to keep mosquitoes from making their way into the take via the overflow tube. IT IS VITAL TO SCREEN EVEN THE SMALLEST OPENING TO PREVENT MOSQUITOES FROM BREEDING.*

You can also attach screening like this:

And there you have it, the tank is now ready to go.

Here are some earlier posts on setting up connected tanks that you might also find useful. In them, I use a different tool for cutting the opening, but it is even more ridiculously expensive than the unibit from the Big Box, so unless you have an electrical contractor friend, don't even try it.

Now I'll show you mine
Rainwater Harvesting: Making the connection
Rainwater Harvesting: Putting a lid on it 

*From time to time, people suggest that I put mosquito dunks in my tanks, and I have done this in the past. In my experience, however, they just don't seem to work. Instead, I find that being extremely diligent about closing off openings is much more effective. So don't get lulled into thinking that you can just drop in a dunk and slack off on this vital part of the construction. Think like a mosquito! Be the mosquito! Find those openings and then close them off.



18 comments:

  1. I love this post, Susan! Thank you. I'm going to borrow your catchment ideas when I build my little house on the other end of this property. I love the look of the galvanized tanks, and the way you've elevated them. The only thing I wonder about is the mosquito screening on the top and whether in my even drier climate it would create a good enough seal on the top. I'll just have to try it out and see...

    ReplyDelete
    Replies
    1. It has worked pretty well here, Susan--even on the Asian Tiger Mosquito. The key seems to be letting the excess drape over the edge.

      Delete
  2. Great ideal. Also thought of using one to grow root vegetables but don't know how well it would work

    ReplyDelete
    Replies
    1. I've got a couple I'm going to set up that way, David. We'll see, I guess!

      Delete
  3. They look so much nicer than those horrible plastic water butts you can buy!

    ReplyDelete
  4. Fantastic info on mosquito blocking, especially the overflow tube - hadn't thought of that! Thanks!

    ReplyDelete
    Replies
    1. I had one tank that was forever getting mosquito larvae breeding--until I figured out that they were coming in through the overflow tube!

      Delete
  5. I think your tanks blend in with the surroundings just fine. I had to look for a couple of them in your photos. Good job.

    ReplyDelete
    Replies
    1. Thanks! I really like the way they look in the garden--as if they are supposed to be there (as opposed to the plastic rain barrels, which to my eye, seem unnatural next to plants).

      Delete
  6. hmm... you've got me thinkin' galvanized stock tanks are the way to go! wish i had one (or more) installed yesterday, as we got a whole 0.4" of rain. my two rubbermaid buckets have about 8" of water in them now, and they only catch water from a small portion of the roof (no gutters). just think of all the water we could harvest, if we only had the infrastructure ready to go...!

    ReplyDelete
  7. I had rainbarrels in Virginia and one of the biggest issues I had was not making them high enough to have gravity assist in the flow of water out the lower spigot. I like the use of your galvanized tanks. Mine were olive barrels, refitted for use as a rainbarrel.

    ReplyDelete
  8. Thanks author for your nice blog and wonderful shared to galvanized stock tank and rain barrel

    ReplyDelete
  9. I searched online last night for this very project! Thank you for posting the instructions in detail. I got all my supplies today--with the exception of the rubber gasket for the interior nut on the 3/4 inch pipe. I am having a hard time finding one with a 3/4 inch interior diameter. What kind did you get exactly, or do you have any suggestions on what to ask for when shopping? Thank you so much! (Becky in Virginia)

    ReplyDelete
    Replies
    1. Becky, the rubber gasket came with the tubing. I got this at Home Depot in the electrical section. Maybe you could print out a photo and take it to Home Depot? Good luck! I hope it works out for you.

      Delete
  10. Susan, thank you! Last night after I posted I searched the internet and may have finally found one that should be workable one at my local Lowe's. If that doesn't work, there is a Home Depot in a nearby city and I just happen to be traveling there on Monday.

    I am so pleased to have found your post about this. I have a new shed on my property and it's near the garden and a perfect candidate for rain capture. And I really like the look of the galvanized troughs, so this is a winner for me. It's been a good learning experience as well--it's moving me into advanced do-it-yourself! --Becky

    ReplyDelete
  11. I saw how rusty the inside was - is it safe to use this water for drinking water (after filtering)?

    ReplyDelete
    Replies
    1. Probably not for drinking water. If that is what you need, you should probably invest in a cistern.

      Delete