Rain Harvesting First Flush and Leaf Diverter Review

Six months ago, I installed a leaf diverter/filter as well as a first-flush system on our rain water tanks that we use for drinking and household water, to ensure we have a clean water supply.

Now that I've had some time to see them both in action, I thought I would share my findings.

What is a leaf diverter?

As the name suggests, this is a device that prevents leaf and other large debris from entering your rain water tank. The mesh filter also prevents insects, particularly mosquitoes, from entering the tank.

While most poly tanks have a filter, this is not always the case for older tanks such as our concrete tanks. In this case, I purchased the "Rain Harvesting" brand leaf diverter from Bunnings.

Here is the link to their product page.

What is a first flush diverter?

This device diverts a volume of water from entering your tank which is likely to contain roof contaminants such as soil/dust, bird droppings, fertiliser residue and other small particles or chemicals that accumulate on your roof between rain events.


Again, I used the one available from Bunnings.

The kit contains the floating ball and associated special T-join that has a moulded ball seat. Also included is the tube emd-cap, which allows for a steady release of diverted water, allowing the tube to empty once rain has ceased, resetting the system automatically.

The kit contains several rubber washers that have different sized pin-holes in them, allowing you to control the rate of water release and therefore the timing for the system to reset. Choice of hole size is based on the size of the diversion tube, which can be quite large. The recommendation is to have as large a tube as possible given your space limitations.

In this photo you can see the floating ball in the background as well as the assembled end cap.

Overall impressions

My experience of installing the first flush diverter was problematic to say the least. The instructions were very unclear. I needed to use several YouTube videos as well as study the individual parts to finally understand how to assemble the unit. This is definitely an area the company could improve in.

However, after finally working it all out, the final system is excellent and works very well. It is easy to clean and would be easy to replace if anything should fail.

I was surprised by how much debris accuulated in the bottom of the diverter pipe, thereby preventing this from entering our drinking water. It was smelly, black mud. On this basis alone I would now never have a tank without a first flush diverter.

The Leaf Beater does as it suggests and was easy to install. The amount of leaf debris that can accumulate on the mesh is quite high, but this does not prevent water from passing through it at a high flow rate during, for example, a thunderstorm.

Once it has stopped raining, it is a simple task to remove the mesh, which is sitting in the device and not clipped or screwed in, and empty it of its leaves and twigs.

Recommendation

I would recommend both these devices. I note that Rain Harvesting now have newer versions of the first flush diverters. My only hope is that they have improved their instructions.

The Leaf Beater is really for people that do not already have a tank mesh filter, but if you don't, then this product will do its job well.

How to Build a Double Bench with Table

I recently built this double bench with a centre table to replace some camp chairs and brighten up the place.

This is from a design that I made on the brilliant Sketchup program based on other designs I found there.

The primary improvement I made was to slope the seat 5 degrees, which leads to a more comfortable sitting position and does not overly complicate the build process if you have a mitre saw.

The Sketchup design can be found here.

The Sketchup model looks like this:

Materials

For all the sides, rails and supports, I used 90 x 45 mm recycled timber.

The front horizontal rail is bigger at 140 x  45 mm. This height is not critical - adjust your build accordingly.

The seat slats are 108 x 19mm floorboards cut down to 86 mm wide. You could use any decking timber.

The table and arm rests were milled from an old piece of timber to 130 x 28 mm. This was custom-milled. As long as they are all the same thickness, the overall piece will look good.

I used 14 - 10g x 75 mm stainless steel screws for the majority of joins.

8 - 10 g 40 mm screws were used to attach the seat slats.

The piece was finished with outdoor decking oil.

Step 1: The Frame

To build the frame you need to cut the correct angles of the rails: 5 degrees for one end and 10 degrees for the other. This leads to an overall slope for the back of 15%.

The first cut to make is the small bevel where the front seat slat will sit. This cut needs to be first so that you can align the timber correctly on the mitre saw. This is a 5 degree cut of only 3mm.

Once you have made this cut, do the other 5 degree cut for the front, then do the 10 degree cut for the back.

Once complete you can assemble the frame:

Step 2:  The Sides

Making the sides is straight-forward. Cut all the pieces, including the 15 degree cut to the back of the top rail and join all the pieces.

In this design I chose to cut a notch in the vertical front pieces to support the front horizontal rail. To do this a did multiple passes on the mitre saw with the depth set to 45 mm (half the depth of the vertical piece). This adds a nice effect to the overall piece. If this is too hard for you, or if you don't have the right tools, just leave this step out and cut your front rail the same width as the rear rail.

To get the pieces square, measure and triangulate and adjust accordingly. If these pieces aren't square, then the rest of the build will be difficult.

Attach these pieces to your frame.

Step 3: Seat Slats

The seat slats need to go on next as you will have to temporarily remove the upper side rail to gain access to drilling and screwing.

I cut a bunch of 9mm spacers to help lay out the slats.

Once you have finished attaching them, reattach your side rails.

 

Step 4: The Back

The back pieces need to be square and all the same length. It is also nice to round them over to take away the bulky feel of the overall piece.

To round them, I drew a semicicle using a round saucer. Try to aim for a radius of about 45 mm (half the width of the timber). Then I cut using a jigsaw. On the recycled hardwood I used, this was quite difficult as the timber burns as the saw turns. Sanding tidies this up.

Once you have your four pieces, attach them to your frame:

The side pieces can be used to stabilise the two at each end, while the middle pieces can do with an extra screw. I used 3 screws in for the middle pieces. All others have 2 at each point (4 in total).

Step 5: The back slats and table supports

The back slats go next to ensure that the back rails are the correct distance apart. If you attach the top slat first, you can correct for any warping in the vertical rails.

Once you have all the slats on, go ahead and attached the pieces that will support the centre table, taking care to align the rear piece carefully to ensure the table will be level. It's best to do this on a level surface and use a spirit level to align the rear piece.

Step 6:  The Table and Arm Rests

Finally, attach your table and arm rests.

I decided to shape the arm rests with a jigsaw to give a nicer overall look, but this is optional. You may alternatively round the rear corners the same as the back supports to soften the look without overcomplicating the build.

I hope you enjoy this design. If you build your own or have any comments or suggestions, please let me know.

An Australian Weather Parser for the RainMachine

I had previously written a comparison of various smart watering systems and have selected the Rainmachine HD-12 as my preferred option.

While there is no local support, I have been able to get the RainMachine working well here by replacing the 110v plug pack with a 240v one from Jaycar.

The RainMachine uses internet feeds for weather predictions and is very U.S,-focussed, as expected, with the majority of weather services localised to the U.S. However, being open to developers there is the opportunity to write your own weather parser for a weather service of your choice.

Here in Australia there is a weather service called Willy Weather and I have written a parser for Australia based on the JSON API from willyweather.com.au.

Instructions and code can be found here: https://github.com/safepay/rainmachine

Willy Weather provide a commercial API that uses the Bureau of Meteorology data and wraps it in a modern API framework that is easy for developers to consume. The first 5000 calls are free, then the cost varies based on data requested, but is around $0.05 per 1000 calls.

This parser I have written detects your location based on your lat/long settings and suggests the closest station ID's. You then enter and save the station ID of your choice and the parser does the rest.

I hope that this can assist anyone else looking for a local Australian weather source for their RainMachine.

I use this parser along with Open Weather Map for good results.