[ST7677]

1.RO and UV are in parallel and not cascaded, in that some UV treated non-RO water is mixed into the RO water to providewater which is more 'normal'. Useless for places with very had water.

2. Most RO tanks have a problem in that Crickets and ants can get in from the vent. So watch out. You should prefer a system where the liquid is visible. The only exception to this is the Zero-B which has a sealed tank. Kent & Eureka Forbes units can be sealed with tape to avoid this problem.

3. membranes last much longer in RO systems with automatuc flushing of the membrane.

I agree is hard water is not an issue than a plain UV should be good enough. I am in a very ahrd water area, and some day will switch over to an RO system. Remember any RO system wastes netween 5 and 10 litres of water for every litre it purifies.

Some corrections here, based on my extensive research before I bought KENT RO+UV few weeks back.

1. RO & UV are parallel in Aquaguard, and based on water hardness it decided which method to use. KENT has both UV and RO in sequencial order. KENT offers 4 stage filteration process Sediment

Please note that UV only paralysis the bacteria for 24 hours (that also if water stays in UV chamber for sufficient time), hence UV water is really fit for consumption within 24 hours. Whereas RO water can be consumed upto six months if it is properly stored.

3. Chlorine in the municipality water kills the RO membrane prematurely. Chlorine is removed by carbon block, so if you ensure that your chlorine block (around Rs. 300) is well maintained the RO membrane (around Rs 1700) will last about 2 years (depending on usage).

Also, RO does NOT waste 5 to 10 liters of water for every liter of pure water. I think you meant to say each tank of clean water, which is 8 liters. In my case I measure it was throwing about 4-5 liters waste water for every 8 ltrs pure water. But I have only 270 TDS level, so for more TDS it might be more.




The reason for going for home water purification vs packaged bottled water is simple for me:
1. Assurance - There is a big parallel business which runs in most metroes on refilling water containers and selling fake mineral water bottles. They even seal the bottles as good as the company does, so there is no real way of identifying what you get. I see a coverage in news almost every quarter.

2. Convenience - no phone calls, no headache, no dependency, no forgetting.

3. No risks - in case of any disruption in packaged water supply chain, or lets stay a bund call, etc, you would not be left stranded without any water.



Also I went with RO+UV over pure UV inspite of reasonable TDS (270) in supply water, as I am concerned about increasing toxins in bangalore water, at least RO will reduce the levels we consume (this user configurable and we have set it to 70).

Too low TDS and water starts tasting bitter - I guess like Aquafina!

BTW - I paid 13k for Kent Grand Plus. It has Sediment filter + Carbon Filter + Micronic Filter + UV Filter + RO Filter.

A.S.Service may be of concern from what I hear and read around. But if I am unable to find a good service dealer I will figure out a DIY.

[sgiitk]

Originally Posted by ST7677

A.S.Service may be of concern from what I hear and read around. But if I am unable to find a good service dealer I will figure out a DIY.

No big deal. Go to the independents, as many of us do. Cheaper, prompter, more courteous. A lot of them are ex Eureka Forbes with 10 year + experience.

My little bird tells me that Kent may also use parallel process. From their site:

Water is first pre treated by Sediment and carbon filter, where after by RO Process. TDS of the purify water is adjusted by adding pre treated (Sediment & Carbon) raw water.
This stream of water is further purified by 11 watt UV lamp sterilized.


This stream refers to the Sediment + Carbon and not the RO Part!

[ST7677]

My little bird tells me that Kent may also use parallel process. From their site:

Water is first pre treated by Sediment and carbon filter, where after by RO Process. TDS of the purify water is adjusted by adding pre treated (Sediment & Carbon) raw water.
This stream of water is further purified by 11 watt UV lamp sterilized.

This stream refers to the Sediment + Carbon and not the RO Part!

No no, it's not like that. I rechecked the water pipes flow and it is like this:
0. Water pressurizing Pump
1. Sediment filter
2. Carbon Filter
3. RO and Micronic filter - water separates into two streams and always flows through both these filters in parallel, but how much amount flows through micronic filter can be adjusted by TDS controller. After coming out of RO and Micronic, two streams combine again and go to
4. UV Lamp.
5. Purified water storage tank

So UV and RO are always active in sequence. There is only a bypass created via Micronic filter (in parallel to RO) to give sweatness to the water.

[PatienceWins]

Originally Posted by ST7677

No no, it's not like that. I rechecked the water pipes flow and it is like this:
0. Water pressurizing Pump
1. Sediment filter
2. Carbon Filter
3. RO and Micronic filter - water separates into two streams and always flows through both these filters in parallel, but how much amount flows through micronic filter can be adjusted by TDS controller. After coming out of RO and Micronic, two streams combine again and go to
4. UV Lamp.
5. Purified water storage tank

So UV and RO are always active in sequence. There is only a bypass created via Micronic filter (in parallel to RO) to give sweatness to the water.

Great!! This is what I also understood by going through the user manual of Kent.

[kb100]

I have been doing some research on this. I also have some insight into this business (I started my career with Eureka Forbes Aquaguard Divn some 20 odd yrs back!)

Bottled water is a BIG grey area - a HUGE parallel industry exists where they fill these branded bottles with water from dubious sources as pass the same on as original. The seals are easily duplicable and none of them use any tamper proof holographic seals etc yet! (I am on my third brand of water within a week! )

Effectiveness of UV varies depending on three things, The intensity of the source(the wattage of the tube), the flow rate (determining the time the water is exposed to the UV radiation) and the level of contamination present.(the higher the contamination, the longer the water needs to be exposed for it to be effective).

Most RO membranes either get clogged, or lose their effectiveness over a period of time - the seals weaken and the pores get bigger and let some bacteria thru. This needs to be addressed in three ways.

1. Please remember the smaller the filter the more easily it gets clogged Hence you need to have at least two stages of sediment filtration - the first should be a 10 micron filter followed by a 1 micron filter. These filters should be in a transparent shell so that one can monitor thier condition and clean/replace them as necessary.

2. The RO membrane itself is under .0001 micron. This will get clogged far far sooner that we think. Therefore it is important to periodically 'Reverse Flush" the membrane to open up the pores. (basically reverse the flow of water). Without this both the effectiveness and the life of the membrane will be severely compromised/shortened.


3. The RO membrane will let some micro organisms thru over time - esp as they weaken (esp around the seals etc). Hence it is almost MANDATORY to have some kind of bacteriological agent after this. There normally are two approaches to this - chemical and UV. Chemical is typically some sort if resin - generally iodine impregnated. The latest claims on UV is that they only 'knock out' some of the viruses - that they don't exactly kill them.

The competition in the domestic RO segment is largely down to to players - ION EXCHANGE (Zero B) and KENT.

I find that the ION EXCHANGE Machine is by far the better of the two - since it incorporates all of the above - specially the three separate stages of sediment filtration(20 and 5 micron though) and their auto flush mechanism. They also use silver impregnated activated charcoal - which is better than regular ACC. (this prevents bacterial growth on the carbon itself)

KENT unfortunately does not have any of this - BUT they have UV (whether the water flow is calibrated is debatable but guess post RO even mild doses may be effective.)

Now this is where I am stuck . My wife suffers from hypothyroidism (Hypothyroidism - Wikipedia, the free encyclopedia). Exposure to iodine is not advisable. Hence Zero B is ruled out unless I can find some method of retro fitting a UV chamber (in place of their last filter) to the machine.

With the Kent machines one is very clearly looking at changing the filters more often - and given their service track record, stocking spares and then DIYing seems to be the only trustworthy option! I am also exploring the possibility of adding the 10 and 1 micron sediment filters BEFORE the intake to the Kent machine. This still wont address the RO membrane flushing issue, but at least will definitely help prolong the membrane life!

I am leaning towards the first option( retrofitting the UV to Zero B!) !

Post Script: FACT -- In MOST towns and cities of India, the water pipes run parallel alongside sewage pipes (for ease of laying, and maintenance)! You can well imagine the risks this imposes over time - esp during monsoons etc! (Some of the pipes date back to pre independence!). An effective filter has become indispensable - Personally I will never live without one!

[sgiitk]

@kb100: Thanks for the excellent description. As far as maintenance is concerned I was forced to go to independents since E-F tried to cheat me and service was pathetic. They never bothered to respond to any complaints. I have a simple filter + UV unit at the moment.

With this group no problems since as the chap calls up and comes every three months by himself. Also, it seems most of them are ex Eureka Forbes. In fact he has just supplied a Zero B to a friend, and will take care of the maintenance on behalf of Ion Exchange.

[rsjaurr]

I also use 20lt bisleri bottles for drinking+cooking purposes.

In peak summer we,a family of 3, use about 2 bottles per week,otherwise one is enough for a week.I pay 80Rs for can bottle for home delivery but i dont mind paying 10Rs extra.

[anToNIcHeN]

Originally Posted by kb100

I was reading that one of these ones come with a membrane 'auto-flush' feature.

How much does the membrane cost? Is the running costs high?

Originally Posted by Raja

Can anyone post their actual yearly maintenance costs on a Kent RO system? Thanks

Guys i am planning to buy a RO water purifier.

Zeroed in 2 models --> Zero B and Kent. Which is a better one ?

I currently use a Aqua guard. Currently Aqua guard costs me 700 odd bucks for 6 month period.
Just wanted to know how much would the normal maintenance charges of Kent and Zero B. my decision would be based on the annual running costs as well as A.S.S of both these products.
So do send me the feed back!
thanks.

[Thad E Ginathom]

I'll have to ask Mrs G for our Zero-B maintenance costs.

First year out of warranty we opted for parts and labour. This was expensive, as it factors in the possibility of the membrane failing.

This year, we went for labour only. We did a simple calculation: if the membrane fails, could we afford to buy another one? Yes, so why pay so much every year even if it doesn't!

Another Question: Salt

Is RO the only thing that removes salt from water? recently our panchayat is giving us salty water. The zero B looks after the drinking water, but my wife hates washing in salty water (I don't care). There's no way we can afford RO on a whole-house scale --- is there any cheaper alternative?

[kb100]

Originally Posted by Thad E Ginathom

Another Question: Salt

Is RO the only thing that removes salt from water? recently our panchayat is giving us salty water. The zero B looks after the drinking water, but my wife hates washing in salty water (I don't care). There's no way we can afford RO on a whole-house scale --- is there any cheaper alternative?

Thad

Contact Ion Exchange (the makes of Zero-B) - they have solutions for salt /brackish water too.

[Thad E Ginathom]

Thanks, kb100.

The only problem with them is their prices! We've been thinking about a water softener for a while (before we started getting the salt in the water). There's is about 50,000, and softeners can be had much more cheaply from the smaller companies.

[ASHISHPALLOD]

Originally Posted by Thad E Ginathom

softeners can be had much more cheaply from the smaller companies.

I have fitted water softener in my house for drinking water.
It works well, cost @rs 2500.
But for large scale, cost may be much more.

[Thad E Ginathom]

It seems that my wife did ask our Zero-B maintenance man about de-salination, and he said RO only.

Zero-B AMC (on our machine)

including all spares: 7,000-plus

labour only: 2,247

[Vid6639]

Hows about the Eureka Forbes Aquaguard Total RO water purifier? Is this any good compared to the Kent?

Aquaguard Total RO Smart Turbo Water Purifier - 100% Safe Water for your Family

[aka_iitd]

Originally Posted by vid6639

Hows about the Eureka Forbes Aquaguard Total RO water purifier? Is this any good compared to the Kent?

Aquaguard Total RO Smart Turbo Water Purifier - 100% Safe Water for your Family

I am also looking to change my existing Aquagaurd eboiling model to some RO model.
Checked Aquaguard/Kent/Zero-B
I talked to the household who have these models.
Aquagaurd is good but setup is big with some small plastic cylinder outside with pipes going here and there
Kent is best in terms of compact and water sweetness
Zero-B I felt some smell was coming after purification which was not there in other 2 models. Owner also said the same.

Note : I am comparing the models in same apartment so water supply is common. Also I am changing as water hardness has increased a lot recently

Edit : I came to know this model "Aquaguard Total RO SMART TURBO" from vid6639 link. Did anyone tried this model. Please let us know the feedback

Originally Posted by ASHISHPALLOD

I have fitted water softener in my house for drinking water.
It works well, cost @rs 2500.
But for large scale, cost may be much more.

What is the size of the water softener
Do we need to change some salt/membrane etc
Any standard company which is providing as I was thinking to add the same in existing Aquagaurd e-boiling model