Effective Rainwater Filter – For rooftop rainwater harvesting – Very low-cost, do-it-yourself filters

Eco friendly ideas & concepts
SAMPATH S
Posts: 32
Joined: October 28th, 2014, 1:00 pm

Re: Effective Rainwater Filter – For rooftop rainwater harvesting – Very low-cost, do-it-yourself filters

Post by SAMPATH S »

Glad to inform that THE BETTER INDIA publication has featured an article on me regarding rain water harvesting..

Please click on the following link to read the same.

https://www.thebetterindia.com/240601/how-to-build-a-rainwater-harvesting-system-at-home-cheap-bore-water-bills-low-cost-diy-bengaluru-ros174/
Raju091117
Posts: 21
Joined: January 15th, 2018, 7:33 pm

Re: Effective Rainwater Filter – For rooftop rainwater harvesting – Very low-cost, do-it-yourself filters

Post by Raju091117 »

Hi sampath,

Can you let us known how birds droppings can be avoided to keep terrace clean..?

Regards
Muniraj
SAMPATH S
Posts: 32
Joined: October 28th, 2014, 1:00 pm

Re: Effective Rainwater Filter – For rooftop rainwater harvesting – Very low-cost, do-it-yourself filters

Post by SAMPATH S »

Glad to know that you are the first one to raise this query.

Birds, like most animals, come to the same place again and again, i.e. it is habit forming. Hence, even when we use certain devices, it will take some time to change the habits of these birds.

Some of the birds like eagle generally perch at edges of the wall, etc. and preferably at the highest place of the building. They are not amenable to most kinds of scaring. For such birds, the best way is to fix bird spikes at such wall edges, etc. These bird spikes are generally available on Amazon, link for one such product is given below:

https://www.amazon.in/Star-Pigeon-Control-Spikes-Polycarbonate/dp/B078SXN24X/ref=sr_1_6?dchild=1&keywords=bird+spikes&qid=1604158759&sr=8-6

However, there are other birds which are not that selective and may sit even on the terrace floor. Since it is not possible to fix the bird spikes in walking spaces, alternatives need to be considered.

One such alternative are electronic bird scares. Unfortunately, such scares are almost exclusively made in China, even though they are sold on Amazon.com or Amazaon India or any other e-commerce sites. As per feedback, most of the solar powered (of course with battery back up) have issues with solar charging. Hence I have used power operated ones, which connect to power outlet using adapters. Sometimes the length of the adapter wires may not be sufficient from the power outlet and the place where the instruments are placed. Hence you may need extension wires. These work on the principle of ultrosonic sound, which are not audible to human ears, but can be heard by birds. Additionally, there are also sonic sound, which can be varied so as not to cause annoyance to humans, especially during nights. Some of the models also have flash lights which work in the dark (night) to scare the birds. If you feel such flashing may cause disturbance to any one, including neighbours, you may choose the ones without flash. Depending on the area of the roof and obstructions, you may have to deploy one or more such devices. Effectiveness of these devices is also not always assured. Hopefully over a period of time it will work. I have three such devices for my terrace placed at vantage points and have helped avoid birds, except in rare cases. This, together with bird spikes as above may effectively reduce the bird droppings.

But it needs lot of patience and ingenuity to carryout these aspects.

On Amazon.in the following ones may be considered:

https://www.amazon.in/Aspe-Sentinel-Ultrasonic-Repellent-Extension/dp/B005JE9JAY/ref=sr_1_1?dchild=1&keywords=yard+sentinel&qid=1604158255&sr=8-1
https://www.amazon.in/Yard-Sentinel-Pack-Ultrasonic-Extension/dp/B01MQCLN45

If you need any further info, I shall try my best to clarify.
Raju091117
Posts: 21
Joined: January 15th, 2018, 7:33 pm

Re: Effective Rainwater Filter – For rooftop rainwater harvesting – Very low-cost, do-it-yourself filters

Post by Raju091117 »

Hi sampath,

Thanks for the detailed response. Am starting constuction in sometime, do i need to takecare of any specific things w.r.t RWH during construction? Pls suggest.

Regards
Muniraj
SAMPATH S
Posts: 32
Joined: October 28th, 2014, 1:00 pm

Re: Effective Rainwater Filter – For rooftop rainwater harvesting – Very low-cost, do-it-yourself filters

Post by SAMPATH S »

Hi Muniraj,

Glad that my reply was found usefuly by you.

Also happy to note that you would be starting construction of your house shortly.

Taking certain steps w.r.t. RWH before starting construction would solve, in my opinion, a lot of problems.

This is the right stage for planning the sump storage tanks. The storage should preferably be taking into account your rooftop area and the likely water usage per day. As a thumb rule, for a rooftop area of about 1000 sq.ft., you may plan a sump of about 25,000 liters. This could be used for both cauvery water/borewell water and rainwater.
It is preferable to have two storage tanks of about 10,000 liters each, sandwitched by a 5000 liter sump. The three sumps could be interconnected at the top as well as the bottom. The 5000 liter sump may be used for inlet of rainwater. You may place a pump in each of the 10,000 liter sumps. The overflow of rainwater from the 5000 liter sump may be directed to either or both the side tanks, by opening the valve at the top. This is to make it easy for any sediments from rainwater to settle down in the smaller sump and to get clear overflow rainwater in the other two sumps. The 5000 liter sump floor may be raised by about 1 foot above the other two sumps. As the 5000 liter sump has no separate pump, to empty it, the bottom valve needs to be opened so that the water may flow to the other sump without the sediment, if any, getting into them. The bottom connection may be about 1 foot above the floor of the 5000 liter sump. The bottom connection opening valve may be placed on the side of the 10,000 liter sump. One of the 10,000 liter sump may be used for cauvery water connection if available, if not at a future date. For operation of the bottom valve, it may be necessary to get into the sump when the water is reasonably low, or you can get a device made with a long rod to open the valve from the top of the sump itself. The top connecting valve may be placed in such a way as to connect from outside, so that the valve may be placed in the middle and can be operated from outside without the need to open the sump tank cover.

My sincere advice is not to go for a borewell. However, you may take a decision taking all other aspects into account.

It is preferable to construct sump tanks with RCC.

For RWH this much planning and execution should be sufficient at the time of starting construction.

Regarding structural stability of the building and the sump construction, you may go with the advice of your structural engineer/architect/engineer.
SAMPATH S
Posts: 32
Joined: October 28th, 2014, 1:00 pm

Re: Effective Rainwater Filter – For rooftop rainwater harvesting – Very low-cost, do-it-yourself filters

Post by SAMPATH S »

Is rainwater safe for household use? How safe is rainwater for drinking?

We have all studied in our school days that rainwater is the purest form of water. But somewhere down the years, our opinion changes from pure to impure.

Water is essential for our day to day activities. We need to essentially drink water every day. Today we are heavily dependent on municipal water supply (for Bangalore it is Cauvery water) and/or bore well water (water supplied by tankers is mostly from bore wells).

As per newspaper reports, in Karnataka, two-thirds of all untreated sewage and untreated industrial effluents find their way to rivers and lakes. But despite this, the river water is considered fit for all domestic needs and is also said to be potable (after chlorination) and bore well water (except to some extent for the hardness-TDS) is fit for all purposes.

I can say from my experience, the rooftop rainwater collected can have a TDS as low as 10. It can vary to some extent and in any case would remain soft water (where TDS is less than 120). Even the water purified through RO (Reverse Osmosis) purifiers would have TDS in the region of 25. The softness of rainwater makes it 100% RO water and is best for drinking, bathing, washing clothes and all other domestic needs.

Rainwater may contain some amount of bacteria. The small amount of bacteria would not in any way an obstacle for all domestic usage (except may be for drinking and cooking).

In any case, the entire stored rainwater can be chlorinated using bleaching powder with maximum chlorine content (to my knowledge we have bleaching powders with 33% chlorine content). After chlorination using this bleaching powder, it is better to leave it for 24 hours for the chlorine to sanitize the water. After this period, it is desirable that the water has a residual chlorine of 2 ppm – parts per million (in any case not more than 5 ppm). This can be checked through simple testing on the spot at a very low cost, using kits commercially available. If the chlorine content is not upto the mark, some more bleaching powder may be added and retested. Once chlorinated this way, there is no room for any complaint regarding the bacterial content in water. Moreover, the residual chlorine would ensure that future addition of bacteria, if any, would also be taken care of.

Periodical testing for residual chlorine may be done and rectification done if felt necessary. The water so stored can be used over several months and even years.

In my case, I am now so satisfied with the water I collect, I rarely chlorinate it.

For drinking purposes, I use a UV purifier to neutralize the bacteria, if any.

The other aspect for drinking water is the pH (level of acidity or alkalinity), measured in the scale of 0 to 14, pH of 7 being neutral, below 7 is acidic and above 7 is alkaline. It is said that one should not drink acidic water, not even neutral water. Drinking water should be alkaline in the pH range of about 8.5 to 9.5 or so. It is said that the water output from RO purifiers is slightly acidic. The rainwater I collect has a pH of around 8 to 8.5. In order to alkalize the water further, there are a few alkalization cartridges which can be used in conjunction with UV purifiers at the final stage. These alkalization cartridges generally enhance the pH of water to around 9.5, thus making it very good for drinking.

With this, I hope, the superiority of rainwater over all other sources of water for every domestic use would be clear.
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ardesarchitects
Posts: 1010
Joined: June 20th, 2009, 2:12 pm

Re: Effective Rainwater Filter – For rooftop rainwater harvesting – Very low-cost, do-it-yourself filters

Post by ardesarchitects »

Hi, Sampath
It's very good to see a detailed explanation about RWH and your own designed RW filter details being posted here.
I would like to add few points regarding rain water purity and usages
1. 99% source of water for rivers, borewells, ponds & lakes is only rain water .
2. The purest water available in this world can only be rainwater, while it travels in rivers it gets added with healthy natural minerals from sand, soil and plants .
3. In the case of terrace rainwater we miss those minerals in the long run, this doesnt mean it's not potable
4. It's always suggested to leave the first two rains of the season to get the terrace clean automatically, further rains can be tapped into the sumps.
5. Bird droppings are part and parcel of nature , it happens in rivers too. Leaving the first two rains will take care of it .
6. I generally don't recommend artificial methods of cleaning the water which will defeat the whole purpose of living with nature, unless we have no other options left.
7. Copper vessels are best to store drinking water that makes the water alkaline automatically without any power or artificial interference. It's the commercial water filter brands that create huge plastic wastes in the name of candles and filters.
8. One can always get customized wall mounted copper containers and fill water from regular basic UV water filters.
9. Adding a big alum crystals in a rainwater sump can solve all the issues of dirt, solid particles, smell etc to sediment at the bottom of the sump. Alum is a very cheap material that you get in any traditional chemical shop. I still remember back then in 90's my grandmother used to add alum crystals in the huge drinking water vessels at home and leave it over night for next day consumption.
10. Most of us would have heard about rama water filters, the most famous & oldest south indian SS water filters. They use simple ceramic candles that are eco friendly , reusable by simple washing and long life - www.ramaappliances.in ,
unfortunately in the name of purity & RO we started drinking chemical filled & zero minerals water.

Regards,
Ar.Praveen.N
Ardes Architects and Interior designers
ardesarchitects@gmail.com
www.ardesarchitects.com
https://www.instagram.com/ardesarchitects
SAMPATH S
Posts: 32
Joined: October 28th, 2014, 1:00 pm

Re: Effective Rainwater Filter – For rooftop rainwater harvesting – Very low-cost, do-it-yourself filters

Post by SAMPATH S »

A YouTube channel has published an interview with me about the EFFECTIVE RAINWATER HARVESTING FILTERS - High Efficiency, Low cost, do-it yourself. The interview is in Kannada.

Link to the video: https://www.youtube.com/watch?v=C1bDSbVD3N8&feature=youtu.be
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