How to install a Leaf Catcher and a First Flush Diverter for Rainwater Harvesting

Connecting a First Flush Diverter and a Leaf Catcher to your rainwater tank is an easy DIY installation which can supply your household with plenty of fresh water! The first flush and leaf catcher are available in 80mm and 110mm. The 110mm first flush diverter is more useful as it boosts the capacity of diverted water of the first flush. Click here to see Recommended Rainwater Harvesting Solutions.

NB: We recommend that you first assemble all of the parts without glue to ensure the system fits correctly against your wall, connecting from your downpipe to your rainwater tank.

What's in the box?

Leaf Catcher (80mm)

  • 1 x Leaf Catcher (80mm outlet)

First Flush Diverter (80mm)

  • 1 x top end cap/adapter
  • 1 x 80mm float ball
  • 1 x 80mm aluminium bracket
  • 1 x 80mm round T-piece
  • 1 x bottom base cap with screw off lid
  • 1 x Valve
First Flush Diverter parts

What you will need

  • 1 x 80mm elbow
  • A drill
  • PVC glue
  • Standard round 80mm and 110mm diameter plumbing pipe, cut to a suitable length for your specific installation

Instructions to install a First Flush Diverter and a Leaf Catcher

Step 1
Cut your existing downpipe at an angle so that it directs the water immediately against the grid of your leaf catcher. There should not be more than 50mm of space between the downpipe and the grid of the leaf catcher.

Downpipe cut at an angle for rainwater harvesting



Step 2
Cut your required length of 110mm PVC pipe to use as the chamber pipe. Leave enough area between the bottom of the system and the ground as space is needed for the end cap to be screwed off for occasional cleaning and space for draining the water.

Step 3
Attach the bottom base cap assembly to the 110mm pipe you have cut.

Step 4
Insert the ball into the chamber.

Step 5
Insert the top end cap onto the 110mm PVC pipe.

Step 6
Attach an 85mm (length) by 80mm (diameter) piece of PVC pipe onto the top end cap.

Step 6
Attach the 80mm T-piece onto the top end cap.

Step 7
Screw the valve onto the bottom base cap. The water can be drained into a bucket or a hose can be attached to the valve.

Step 8
Then attach the Leaf Catcher onto the First Flush Diverter.

Step 9
Add a 80mm pipe and elbow to join the first flush to your rainwater tank.

Step 10
Position the parts underneath your gutter to make sure it fits correctly.

Step 11
Then glue all the pipes together using PVC glue, but do not glue the leaf catcher to the first flush diverter.

Step 12
Then mount the entire assembly using the brackets.

How does it work?

As the water level in the first flush diverter chamber rises, the ball floats and rises. Once the chamber is full, the ball rests on a seat inside of the chamber, preventing any further water entering the diverter. The subsequent flow of clean water is then automatically directed along the pipe system through the T-piece into the rainwater tank.

The First Flush system will divert any small pollutant from your roof and gutters into a separate pipe chamber so it does not enter your rainwater tank. The first flush of water from the roof may contain bacteria from decomposed insects, lizards, bird droppings, as well as sediments, waterborne heavy metals and chemical residues.

The Leaf Catcher will help with leaves and larger debris but cannot stop small bits like dust and bacteria. This is why it is recommended that you also install a First Flush Diverter.

Recommended Rainwater Harvesting Solutions

Leaf Catcher
80mm Leaf Catcher
80mm First Flush Diverter
80mm First Flush Diverter
110mm First Flush Diverter
110mm First Flush Diverter

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