Harvesting Rainwater

Dtp1979

yellatdave wrote: »

Forgot to mention 2011's point on algae growth. Algae need sunlight, so you'll have that problem if using clear/translucent tanks like IBC's. Paint the plastic a dark colour or cover the tanks with a blackout material to avoid.

Mine would be in total darkness because I'd have them insulated and weatherproofed

wicklow_hills

there's a lot more to this rainwater harvesting business that you've considered
if you want it for anything other than watering the garden and cleaning the car

the big issue is safe water storage

there's a company in Newtown that are experts in this area: http://www.rainsafewater.com/

Annasopra

Moved from Greystones/Charlesland forum to Sustainability and environmental issues

Crazy Eye

wicklow_hills wrote: »

there's a lot more to this rainwater harvesting business that you've considered
if you want it for anything other than watering the garden and cleaning the car

the big issue is safe water storage

there's a company in Newtown that are experts in this area: http://www.rainsafewater.com/

over 2000 euro for that . about 200 euro worth of parts off of ebay and you would make it yourself with some diy skills . very handy for times like this when dublin council are completely shutting off mains water to the capital from 8pm each night .

zagmund

We had a similar system put in recently when the house was undergoing a complete refurb. Here's a few observations - the pump to bring water from the storage on the ground floor to the attic isn't terribly efficient, so running costs on that are higher than computed above. Basically, every time you flush the loo and use up a couple of litres the pump comes on for 10-15 seconds and goes off again. So, it's a series of small volume lifts over time rather than one big one. If I could get my DIY hat one one of these days I could possibly tweak it a little so that it waits for a greater drop in tank level before doing a lift and then lifts more.

The biggest user of electricity that I can find is the valve that sits between the harvest feed and the mains feed. For some (possibly legitimate/possibly doubtful) reason it's normally open and needs to be powered to be closed. Since the normal state is closed (because we have harvest water and need to close the valve to keep the mains shut off) it is using power 24 hours a day for most of the year. It's not a huge amount. I don't have the figures to hand for the running cost. A manual valve would do the job just as well and since it's only supplying the loos, a situation where we forget to open the valve (to allow mains water) isn't going to result in anything too bad. Feeding a dishwasher or other system could have more problems with a manual valve.

I think we have something like a 900l tank outside and whatever a normal domestic attic tank is inside. Over this Summer we ran dry (and so switched to mains) for maybe 10-14 days. Possibly a little more, but not much. This would have been for toilets and almost no garden watering - this year wasn't a good year for the garden.

We installed the system as a degree of future proofing - the payback may be long, it may be short. One thing is for sure - when the water charges come in we will be saving money (even if only a little) every time we flush the loo. Forever. I've lived in Ireland long enough to know that charges only ever go in one direction.

z

ted1

2011 wrote: »

Unfortunately untreated/filtered rain water is good for watering the garden and little else.

Algae in the rain water will cause it to turn yellow with a green slime forming surface quite rapidly.

This may interest you:

http://rainwaterharvestingsystemsireland.town.ie/

A true rain water harvesting system looks after that with Uv treatment and filters.
My brother has a 2500 litre tank under his patio which treats the water then pumps it up to a tank in the attic fir use in non drinking use

Crazy Eye

ted1 wrote: »

A true rain water harvesting system looks after that with Uv treatment and filters.
My brother has a 2500 litre tank under his patio which treats the water then pumps it up to a tank in the attic fir use in non drinking use

any photos of the tank and system ?
how many in the house ? you wouldnt be too long getting thru 2500l of water in longer dry spells of weather though .

Dtp1979

ted1 wrote: »

A true rain water harvesting system looks after that with Uv treatment and filters.
My brother has a 2500 litre tank under his patio which treats the water then pumps it up to a tank in the attic fir use in non drinking use

Does he use it for showering too?

ted1

Dtp1979 wrote: »

Does he use it for showering too?

I'll check with him. It's actually a 3000litre, here's a blog that was done when he was doing the house up.

http://www.jharchitecture.ie/category/south-dublin-ext-refurb/

Crazy Eye

ted1 wrote: »

I'll check with him. It's actually a 3000litre, here's a blog that was done when he was doing the house up.

http://www.jharchitecture.ie/category/south-dublin-ext-refurb/

nice project there .can you find out who supplied that underground tank please ? i think its either a uk or german made tank but would like to know where he got it from here in ireland .

Pete M.

I've had a RWH system in use for the past 6 or 7 years.
Put it in on a new build, so maybe my experience not so relevant for retrofit.

But I just wanted to say re: algae and treatment etc. that it is my experience that when being used for non-potable purposes, that simple screen filtration is more than adequate.
tbh I don't even clean the screen that much and when i think of it, which isn't often, I lash a bit of sodium hypochorite into it.

It is used for the washing machine and the toilets and there is also an outside tap and the quality has always been absolutely fine.
Clothes are fine, jax are fine, all is fine

The tank is underground, 4000L, pumps supplied and I got it from Shay Murtagh (No ties to this supplier. It's just who I used at the time).

I'm looking forward to seeing how much it will save me on the auld rates when they come in.

ted1

Crazy Eye wrote: »

nice project there .can you find out who supplied that underground tank please ? i think its either a uk or german made tank but would like to know where he got it from here in ireland .

He doesn't know. The architect spec'd it and builder provided it

zagmund

FYI - we've been on mains water for the last 10-14 days.

z