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.