How to stop water tank inlet screen from clogging up

I have a water tank with something like this in the hole in the top to keep mosquitoes out:

https://www.bunnings.com.au/rain-harvesting-400mm-tank-screen_p4816370

The pipes feed water into it, and it's supposed to flow through it, but it clogs up with silt, and in heavy rain it overflows onto the ground. I've pulled off the mesh for now. Is it normal for this to happen?

Find more posts tagged with

Plumbing

Comments

MitchellMc

Hi @pstq,

How often are you cleaning out the mesh? In an ideal world where your roof and gutters are immaculately clean, you'd never get any buildup here. However, in reality, that is simply not the case. There's a whole heap of organic material in the system. If you are seeing this mesh blocked every other week, then it might be time for a thorough cleanout of your gutters, as they could have a buildup of organic material in them. However, this looks to be more slime/algae than material being washed through the system, and I suspect regular removal from the mesh is needed.

I don't personally have a rainwater tank, but with a mesh like this, I'd presume it needs to be cleaned out at least every 2-3 months. The finer the mesh, the more regular the cleanout.

Hopefully, any of our members running a similar setup might like to add to the conversation.

Please let me know if you have any questions.

Mitchell

JoeAzza

Hi @pstq

I have a water tank with a run off bypass pipe for leaves and dirt which prevents the majority of dirt/leaves going into the water tank

I found this video online that will show you how it's done.

https://www.youtube.com/watch?v=wOumD-IFfBg

This is my simple setup, I still need too drain out and remove the cap to clean out, I'm sure their is a better way of do this, please see the video attached.

IMG_2529[1].JPG

Here is a fitting to make clearing the leaves instead of using my set up. Maybe @MitchellMc can give some advice on installation of the item

MitchellMc

https://www.workshop.bunnings.com.au/discussion/comment/17526#Comment_17526

@pstq,

I believe @JoeAzza's bypass pipe is also called a first flush diverter. Here's our Rain Harvesting 90mm First Flush Downpipe Diverter which you could install into your system. It prevents sediment, bird droppings, ****, insects, mosquito eggs and debris from entering the rainwater tank.

Mitchell

pstq

https://www.workshop.bunnings.com.au/discussion/comment/17526#Comment_17526

@JoeAzza is your system just a T with a pipe leading down to a sealed off end? Is the idea that the first lot of dirty water will fill that and the dirt will settle in it? How often do you have to clean it out, and do you find much in there?

Unfortunately I'm not sure if I can fit a first flush diverter. The height difference between the spouting and the tank inlet is only a centimetre or so.

pstq

https://www.workshop.bunnings.com.au/discussion/comment/17523#Comment_17523

@MitchellMc yes it's clogged with fine silt and maybe algae. I fitted that mesh just 3 months ago, as the original mesh had fallen to bits. (I've had this tank since 2008, but only recently connected it up!)

I'd better clean it and put it back.

EricL

Hi @pstq

That "T" junction that @JoeAzza has attached to his downpipe is a version of the Rain Harvesting 90mm First Flush Downpipe Diverter. It can be installed along the horizontal run of your downpipe, preferably as close to the house as possible. It doesn't have to be right next to the water tank. To help with the removal of dirt and debris in your gutter, I suggest installing a Rain Harvesting 90mm Leaf Beater Rain Head. It has a fine mesh filter that will filter out debris before it reaches your tank.

Would it be possible for you to post a photo of your downpipe set up from your house to the rain water tank? This will give us a better idea of your setup. We can then make recommendations where to attach the first flush and the Leaf Beater. The best time to clean your first flush is after a heavy downpour.

If you need further assistance, please let us know.

Eric

pstq

https://www.workshop.bunnings.com.au/discussion/comment/17543#Comment_17543

I get it now. Yes, I could fit the first flush diverter. Although my pipes are 80mm, and that's 90mm. Can I just fit two of these adapters?

https://www.bunnings.com.au/icon-plastics-80-90mm-round-pvc-downpipe-adaptor_p4770457

Probably I just need one of those, and I can replace the rest of the 80mm pipe with 90mm.

Here's the setup. Water runs from the house guttering onto the verandah roof just visible on the right, then into the garage guttering, then into the guttering of the little steel shed, then into the tank. I could fit the diverter between the steel shed and the tank. There's another pipe from the back of the steel shed to the tank, but maybe that catchment is too small to worry about. Note the the pipe from the shed to the tank is nearly horizontal, so I can't fit the rainhead there.

I cleaned and refitted the mesh. It was actually full of silt. I thought it was just three months accumulation, but it's probably a couple of years. I reused some pipe that ran directly from the garage to the tank with a big sag in it, and it had a ton of dirt in it. Can't remember if I cleaned it out first. Maybe it all got washed out by the rain.

MitchellMc

https://www.workshop.bunnings.com.au/discussion/comment/71410#Comment_71410

Using an Icon Plastics 80-90mm Round PVC Downpipe Adaptor will allow you to switch between 80 and 90mm PVC pipe.

Fixing the rain head will be a bit difficult if there isn't any place to have the water drop into it. Rain heads are just a convenient way of removing larger materials like leaves from the system. However, it doesn't appear like you have much of a problem with leaves. The first flush diverter will be what helps the most with your sludge build-up. I'd suggest starting with one of those to see if it solves your issue. You'll likely need to do a three-monthly cleanout.

Mitchell

Child Item