Navitron Renewable Energy and Sustainability Forum

Green Building and Design => Rainwater Harvesting / Grey Water Recovery & Processing => Topic started by: Photosolo on January 12, 2020, 08:02:31 AM



Title: Water filtration - off grid
Post by: Photosolo on January 12, 2020, 08:02:31 AM
Hi apologies if thereís a great deal of these questions already?
I promise Iíve tried the search facility..
Iím looking for advice on finding a water filtration solution.
We are off grid so Iím always looking at options to remove the need for electric.
So it seems:
No UV filter
No reverse Osmosis
Iíve seen talk of ceramic filters (0.2 micron) combined with a carbon filter.
Is there anyone on here using anything like this?
Thanks for help in advance.
Dan


Title: Re: Water filtration - off grid
Post by: chasfromnorfolk on January 12, 2020, 09:40:32 AM
You donít say what youíre wanting to filter out, or what the filtered waterís wanted for, but these people: https://www.andrewswater.co.uk/water-filter-systems/

were very helpful when we had a high nitrate content in our well water for a while, successfully reducing that to LA -acceptable levels at a dedicated drinking water point.

Repeated testing of the Ďfiltered faucetí sample against an Ďuntreated tapí sample revealed a few years later the ground water had cleared, so we stopped using it or replacing filters. They were about £80 a year.

Hope that helps,
Chas


Title: Re: Water filtration - off grid
Post by: billi on January 12, 2020, 09:45:53 AM
Hi ,  i used this one (called Ultrafiltration) ,  as a  inline ( needed a pump anyway to built up reassure)  for years to filter  pond water , to be used  in the house
and was happy with it   https://www.memfilwater.com/filter_dss-540s.php
The reason i bought it there , was simply that the same systems  would have cost 5 times more in Germany or the UK

Billi




Title: Re: Water filtration - off grid
Post by: Photosolo on January 12, 2020, 10:03:13 AM
Apologies... itís to ensure safe drinking water to the house.
As itís coming from a mountain stream, I plan to pump to a holding tank at the top of our land so we have a consistent flow without worrying about a possible dry spell. Although the previous owner said the stream only run dry once in 20 years.
Thereís no live stock on the surrounding land itís all forestry. Not to say a random stray sheep or deer couldnít fall and drown up stream (or rodent). Mmm
I guess we should get the water tested next for specific requirements. But my main concern is pathogens / anything that could cause harm.


Title: Re: Water filtration - off grid
Post by: billi on January 12, 2020, 10:54:34 AM
If you  have your intake  up that stream , you have pressure   and possibly much nicer water, than if you tank it .
So  just use  tanked water for an emergency time ??

So ultrafiltration (if pressure is high enough) would work , and if choosen big enough to allow a decent flow , no need for any electricity then
https://www.freshwatersystems.com/blogs/blog/how-an-ultrafiltration-membrane-works

to one tap you can ontop ad something like the Ozonboy attached direct to a tap  , i love it  , here we talked about  filters ...https://www.navitron.org.uk/forum/index.php?topic=26541.15

Billi




Title: Re: Water filtration - off grid
Post by: Photosolo on January 12, 2020, 10:57:35 AM
Thanks Billi
Very helpful stuff👍


Title: Re: Water filtration - off grid
Post by: Bodidly on January 12, 2020, 11:51:34 AM
All we have ever had is a system that looks much like this https://www.directwaterfilters.co.uk/water-problems/chlorine-and-chloramine/1-year-whole-house-water-filtration-system.html One course filter and a second finer one.


Title: Re: Water filtration - off grid
Post by: camillitech on January 12, 2020, 02:08:59 PM
Hi PS,

Build yourself a slow sand filter https://en.m.wikipedia.org/wiki/Slow_sand_filter cost you next to nothing, no electric required and filters just about everything.

Cheers, Paul


Title: Re: Water filtration - off grid
Post by: Photosolo on January 12, 2020, 02:29:19 PM
Thanks for the help everyone, lots of helpful info. Really appreciate it👍


Title: Re: Water filtration - off grid
Post by: heatherhopper on January 12, 2020, 04:04:37 PM
As already stated it all depends on incoming water quality and desired filtered quality but I cast another vote for a simple sand filter. Installed one on the incoming side of our storage a couple of years ago and it has proved the most effective part of the system.

Have tried numerous passive filter types over the years but now have only a single 10" housing downstream in which I use cheap <1 micron wound rope cartridges and these need changing infrequently.

I have added a 30W UV lamp recently to keep the other half happy and I would suggest if you are concerned about pathogens this is the best bet. Because of it's power consumption I suspected I might let this fall into disuse come bulb change time but truth is it has made not a jot of difference to when we need to run the generator so it may stay.


Title: Re: Water filtration - off grid
Post by: Moxi on January 13, 2020, 10:37:32 AM
Most of the water companies use sand filtration to polish their potable water, activated carbon is used in areas where there may be a taint or odour to the water, and then a dose of ozone, chlorine or UV to kill pathogens (dose and frequency linked to the areas source water quality) so as has been suggested - have the water source checked and proceed from there.

A word of caution though to ensure your source has the same conditions during winter and summer, I see you have noted its only run dry once  but flow conditions can slow in summer leading to lower oxygenation pH can decrease leading to increases in metals and other compounds passing in to solution, during the autumn leaf and needle fall can taint the water and give rise to colloidal suspensions and so quality can change dramatically through the seasons.  None of these factors prevent you using the water they just indicate what additional steps are needed to enjoy the water resource safely.

Moxi


Title: Re: Water filtration - off grid
Post by: Photosolo on January 13, 2020, 01:45:32 PM
Nice one Moxi
Great advice. I will attempt to have the water tested soon.
Would you recommend having the water checked by my local environmental health officer or is that over kill ?
I assume there's plenty of private companies offering to test online.


Title: Re: Water filtration - off grid
Post by: Iain on January 13, 2020, 04:15:01 PM
Hi

Quote
Would you recommend having the water checked by my local environmental health officer or is that over kill

Would be tempted to keep it under the radar. I think others have had issues with too much official interference after a simple request.

Iain


Title: Re: Water filtration - off grid
Post by: Moxi on January 13, 2020, 04:50:43 PM
I would seek out a qualified lab suitable for testing potable water and tell them the parameters you are looking for - I doubt the local environmental officer will have access to suitable facilities and is likely to complicate matters and increase costs by asking for copies and possibly asking unnecessary questions about abstraction licences etc

Moxi


Title: Re: Water filtration - off grid
Post by: Barrie on January 13, 2020, 05:33:44 PM
I wouldn't like to comment how officious the EHO could be but when we had a case of blue-green algae we asked the EA to come and look and they turned out within three hours and we had the results the following day (all free).

This confirmed the presence of the toxins but not at dangerous levels and the results were accompanied by lots of useful advice on what activities were safe and what were not.

They then returned two/three weeks later for a follow up test which confirmed the levels were back to normal.

Barrie


Title: Re: Water filtration - off grid
Post by: billi on January 13, 2020, 08:40:05 PM
I tested my water supply from a "memade" pond  with surfacewater flowing in , i got it tested twice  first time befor  the Ultrafiltation filter went in  and 3 month later after , first results where beside manganese and iron problems here ,  that it failed to be regarded as potable water , second test said its absolutely fine :)

in the ten  years in operation , none of us ever had a problem , many  of the school friends  of my son ,  had more problems with the council supplied water   ( but i am not sure if thats related to water )

billi


Title: Re: Water filtration - off grid
Post by: woodi on January 30, 2020, 10:32:28 PM
Hi, yes we harvest rainwater, into a chain of IBC containers, around 5000 litres. It's coarse filtered through a sock filter going in, to remove any bits, and then a mesh filter before the pump, to protect it. Then we use standard 10" filter housings (screwfix), with a particulate filter, then a carbon filter, and last a ceramic. The first two are disposable, the ceramic is cleanable. It slows down the flow by at least 50%, but you can get housings that take multiple cartriges that will allow greater flow. The particle filters are a few quid, the carbon ones around £10 and the ceramic ones about £30. They're a standard size so its easy to get replacements, and our water has tested nice and clean coming out of the other end.  I get it tested annually.
Obviously it helps if you have a clean roof, keep your gutters clean etc which will make life easier on the filters. All works well, I know a few other people using the same setup and they're pleased with it too. Its the lowest cost, simplest way to provide whole house filtration that I've found.