Best value large underground rainwater harvester?

[doobin]

As above, the bigger the better. Anyone know of anything particularly good value for money?

 

[V8Druid]

As above, the bigger the better. Anyone know of anything particularly good value for money?

this is going to be interesting .... have been thinking about this for some time ..... get enough of it

 

[Smiffy]

As above, the bigger the better. Anyone know of anything particularly good value for money?

For big attenuation tanks we use soak away crates wrapped in dpm sheet lol and plastic weld it with blow torches. Only problem would be cleaning them out.

 

[Canal Navvy]

For big attenuation tanks we use soak away crates wrapped in dpm sheet lol and plastic weld it with blow torches. Only problem would be cleaning them out.

I wonder how it would work putting trickle irrigation pipes at the bottom and blowing compressed air through to get the solids into suspension for pumping out

 

[charlie2]

put some massive rainwater tanks in on an army camp they planned to use the water for flushing the toilets the problem was the rainwater from the roofs was far from clean and would block the valves in cistern they did not put any filtering between downpipes and the tanks, not sure if it ever got sorted properly. it was a big thing about being eco friendly just poorly thought out. the cost must have been huge probably would have been cheaper to drill a borehole and build a filtering and pumping plant.

 

[Bob]

Tanks aren't cheap

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[6feetdown]

Tanks aren't cheap

Rainwater Harvesting Systems | Rainwater Storage Tanks | Drainage Superstore®

Shop Drainage Superstore today for top-quality rainwater harvesting systems and tanks! From big brands like Graf, order now for fast & secure delivery!

www.drainagesuperstore.co.uk

I priced a large 1 for a cricket club last year it wasn't cheap and never heard back from them

 

[DaveDCB]

Depends what it’s going to be used for I guess? You could use anything depending on the end use of the water…

 

[Grahams]

I priced a large 1 for a cricket club last year it wasn't cheap and never heard back from them

Obviously depends how much you were charging to install it, but I don't think a 5000l tank with built in filtration to drinking water standard for less than £3000 including VAT is too bad.

 

[Lancs Lad]

Just make sure the Mains top up system (they also use it as a header for pressure) is working correctly...heard of one recently where the ballcock stuck ...got a water bill for £30k 🫣🫣

 

[doobin]

This is purely for storing rainwater to water the (large) garden.

 

[Gunners]

In my experience they don't really work. When you want to water the garden it doesn't rain, so you use the tank full you have and that's topped up by the mains anyway after that. And when its raining like mad, the tank is already full because its topped up by the mains..... Unless you water WHILST ITS RAINING!!! you don't really save much.
The proper tanks are really the only way to go, they come with built in filtration (which has to be maintained!!) or as others have said - fills with silt. The pumps need to be spec'd to the system you are looking to install in the garden. Sprinklers take a lot more pumping to keep going than leaky hose for example.
Personally, I'd be selling them the idea of thicker mulch around their plants and just have a basic leaky hose setup for their bigger shrubs and trees that runs off a timer on the mains.
If they want the full irrigation setup then you will no doubt still need a tank to ensure enough water supply throughout the sequence - but the effort of trying to top that up with rain water is pretty futile as the mains will always fill the tank first.

 

[Giles]

ive built two now for clients one 10K litre one for stable block for washing yard down and one for camp site welfare block both harvesting rainwater both working well and took a bit of fine tuning, campsite one has main backup on float valve.

I just got a cheapish 10k litre tank and an on demand pump then collected all rainwater galleys into a silt trap and use a couple of geo textile filters, pump floats on flat so is always 4" below surface.

 

[JerryRtilt]

We've installed a few over the years, mainly on up market new builds where the client likes the idea and it ticks the appropriate 'green' box, what they don't realise is it takes a lot of water to run sprinklers for any significant length of time as @Gunners says, a 5000lt tank sounds huge to them but is empty in no time, if you try to explain they actually need something possibly ten times the size to be effective they rapidly go of the idea

 

[V8Druid]

Obviously depends how much you were charging to install it, but I don't think a 5000l tank with built in filtration to drinking water standard for less than £3000 including VAT is too bad.

I agree .. didn't think the prices for the 5000 units were silly at all considering their equipment

 

[DaveDCB]

Customer of mine has an old railway truck trank under his yard for rainwater, uses it for his volume washer. Water is abit rusty which I can’t image does the washer any good really..

 

[Monkeybusiness]

Surely the mains top-up only kicks in when the tanks are nearly empty, and just keeps a minimum level in the tank?

 

[V8Druid]

Having the mains connected to them kind of negates the purpose really .. and gets expensive I'd imagine.. we don't have mains so'd not be connecting our spring into anything I installed, but the prospect of having a large volume tank for wash off/garden water would be good, as we sure as hell get enough wet stuff to keep any tanks full, a lot of the time.
don't think 5000l would be enough though ?

 

[doobin]

In my experience they don't really work. When you want to water the garden it doesn't rain, so you use the tank full you have and that's topped up by the mains anyway after that. And when its raining like mad, the tank is already full because its topped up by the mains..... Unless you water WHILST ITS RAINING!!! you don't really save much.
The proper tanks are really the only way to go, they come with built in filtration (which has to be maintained!!) or as others have said - fills with silt. The pumps need to be spec'd to the system you are looking to install in the garden. Sprinklers take a lot more pumping to keep going than leaky hose for example.
Personally, I'd be selling them the idea of thicker mulch around their plants and just have a basic leaky hose setup for their bigger shrubs and trees that runs off a timer on the mains.
If they want the full irrigation setup then you will no doubt still need a tank to ensure enough water supply throughout the sequence - but the effort of trying to top that up with rain water is pretty futile as the mains will always fill the tank first.

Good shout on filtration. This will actually be filled via a land drain, which runs quite a bit even after rain has long since finished.

 

[Giles]

Only need mains top up if plumbed into toilet flushes etc