[LBWCS]

Hi lads

I have a purefreedom van mount and ro. Need to change the pre filters, I have two 20" curently. Looking in gardiners and the fibredyne new ones seem to be better. It says on there replace the two that i currently have with just one fibredyne, am I understanding that correctly?

[d s windowcleaning]

Yes you only need the 1 fibredyne filter , but you might aswell put a sediment filter in with it will last longer then but its not needed.

[andyM]

Gardiners sell the genuine Pentek Fibredyne filters.
And very good they are too.....

[SeanK]

Total waste of money but go for it if you have it to burn.
A fibredyne pre filter will cost you almost £30 including vat and will give you 75700lts before
changing.
Lets say you make 500lts of pure a day a 60/40 waste to pure then that's 1200lts per day over a week
that's 6000lts. Give or take a few litres.
That means you will need to change them every 13 weeks or so or between 3 and 4 times a year depending
on how it falls.
So you will be spending between £90 and £120 a year to protect a £220 membrane (lets say it a 4040)
Is it any  wonder the sellers seem to promoting these filters when two 10 inch pre filters at about a tenner for both
would do the same job.
Even if you where to change them every 3 months your talking under £40 a year to do the same job.

[Alex Gardiner]

Total waste of money but go for it if you have it to burn.
A fibredyne pre filter will cost you almost £30 including vat and will give you 75700lts before
changing.
Lets say you make 500lts of pure a day a 60/40 waste to pure then that's 1200lts per day over a week
that's 6000lts. Give or take a few litres.
That means you will need to change them every 13 weeks or so or between 3 and 4 times a year depending
on how it falls.
So you will be spending between £90 and £120 a year to protect a £220 membrane (lets say it a 4040)
Is it any  wonder the sellers seem to promoting these filters when two 10 inch pre filters at about a tenner for both
would do the same job.
Even if you where to change them every 3 months your talking under £40 a year to do the same job.

These Fibredyne filters are actually better value than standard pre-filters that you are recommending. Lets look at the actual comparison based on the actual chlorine reduction life of the filters:

2x Standard 20" filter pack (1x sediment and 1x Carbon Block as are on Pure Freedoms website and many others)
Average chlorine reduction life span = 22,000 litres (generally not published by WFP re-sellers as this figure is surprisingly very low)
If using your above figures of 6000 litres per week then technically the standard filters would need changing every 3.6 weeks. This gives a yearly cost of £330 (inc. VAT)

1x 20" Fibredyne pre-filter
Average chlorine reduction life span = 75,700 litres
If using your above figures of 6000 litres per week then technically these Fibredyne filters would need changing every 12.6 weeks. This gives a yearly cost of £118.80 (inc. VAT)

This means that if changed according to manufacturers recommendations then the Fibredyne filters would save you £211.20 per year.

Of course most window cleaners do not maintain their water pre-filters as per the actual life of the carbon pre-filters. Most 'get-away' with 3 or 4 months with no adverse results - this is up to them and of course a similar policy could be applied to Fibredyne filters as well.

If wanting to prolong the life of the Fibredyne filters, as has been suggested then fitting a sediment pre-filter will help greatly and these are usually very cheap.

[SeanK]

Exactly, most guys don't stick to the recommended change intervals so like I said every three months
will cost you £40 a year, so even if you change the Fibredyne twice a year its still going to cost more.
Yes most guys will let a filter go for a few weeks or maybe a month beyond its recommended usage limit but will get slightly nervous the longer it goes after that.
Let a Fibredyne go 6 months before changing I don't think so.
We all know who the real winners are from these filters.

[Alex Gardiner]

Exactly, most guys don't stick to the recommended change intervals so like I said every three months
will cost you £40 a year, so even if you change the Fibredyne twice a year its still going to cost more.
Yes most guys will let a filter go for a few weeks or maybe a month beyond its recommended usage limit but will get slightly nervous the longer it goes after that.
Let a Fibredyne go 6 months before changing I don't think so.
We all know who the real winners are from these filters.

I would disagree with this as a retailer and I will show why  

Users can (and often do) ignore the chlorine reduction life of standard filters, but it will of course shorten the life of the RO membrane from a 5 year average to about a 2 year average.

So looking as a retailer at the following scenario:

Option 1 - 6,000 litres per week, changing standard twin 20" pre-filters every 3 months (which is way outside of recommendations) and a 4040 HF4 membrane every 2 years

Total operating cost over a 5 year period = £876

Option 2 - 6,000 litres per week, changing 1x 20" Fibredyne filter every 3 months (which is the recommended life) and a 4040 HF4 membrane every 5 years

Total operating cost over a 5 year period  = £804

As we also make a higher margin on the standard pre-filters than the Fibredyne filters coupled with a smaller turnover for us if users take the Fibredyne option then we would be financially better off if all clients stuck with the standard option.

So why do we stock and recommend the Fibredyne option? - because it makes financial sense for our clients, it involves less time spent changing filters and undoing housings and also saves on storage and shipping costs as they take up less space.

The great thing in life is that there is the option of both methods - as long as clients are fully informed as to the real world costs of each option.

[SeanK]

There is absolutely no evidence that not changing pre filters to their recommended usage limits
shortens the life of an R.O.
Even the filter manufacturers put a depending on the water quality as a get out clause.
There are too many different things that can cause an R.O. to fail to blame it on the pre filters.
But here is a true fact, if you change the fibrebyne filter within the recommend usage levels you will have
spent the same amount over two years that would have bought you a new membrane.
Going by the water usage Iv quoted above.
So even if you do buy cheaper filters and don't change them as often as you should your not going to be that
far out of pocket even if the worst happens.
Lets say you don't change a filter at all and you R.O. lasts only a year your still going to be no worse off.

[SeanK]

4040 HF4 £220  2.5 membranes over 5 years £550
4 sets of budget filters £40 yearly
Over 5 years £750.
4040 HF4 £220.
5 years worth of fibredyne filters £600.
Total £820 so you could even buy three membranes over 5 years and be no worse off.

 

[Alex Gardiner]

There is absolutely no evidence that not changing pre filters to their recommended usage limits
shortens the life of an R.O.
Even the filter manufacturers put a depending on the water quality as a get out clause.
There are too many different things that can cause an R.O. to fail to blame it on the pre filters.
But here is a true fact, if you change the fibrebyne filter within the recommend usage levels you will have
spent the same amount over two years that would have bought you a new membrane.
Going by the water usage Iv quoted above.
So even if you do buy cheaper filters and don't change them as often as you should your not going to be that
far out of pocket even if the worst happens.
Lets say you don't change a filter at all and you R.O. lasts only a year your still going to be no worse off.

Hi SeanK

To say that there is no evidence that not changing pre-filters regularly does not shorten the life of an RO membrane is just not correct. If you do not believe my own experience in the field then ask any water treatment expert.

Either way it does not really matter to us particularly as we sell both types of filters to clients and also replacement RO membranes 

[LBWCS]

thanks for the responses, I didnt realize a lot of this info! I use no more than 1200 litres of pure a week, on a 4040.I dont know my rejection rate. Alex thanks for your honesty. I dont really want to spend any time faffing around with changing filters so if i bought the sediment filter and a fibredyne, am I ok for 6 months?
Also Alex have you a date for the alloy camera mount and the new over spray system?

[Alex Gardiner]

thanks for the responses, I didnt realize a lot of this info! I use no more than 1200 litres of pure a week, on a 4040.I dont know my rejection rate. Alex thanks for your honesty. I dont really want to spend any time faffing around with changing filters so if i bought the sediment filter and a fibredyne, am I ok for 6 months?
Also Alex have you a date for the alloy camera mount and the new over spray system?

If you are producing 1200 litres of pure water a week and say you are on a 60/40 ratio, then you will be using approximately 3000 litres a week. This means that a Fibredyne 20" filter on its own will last you for 6 months. If you add a sediment filter then this will give greater clogging protection for your system and help maintain flow rates, although not totally needed.

The Alloy Camera Mounts and the Overspray are arriving towards the end of this week and will be available on the website as soon as they land.

[LBWCS]

thanks for the info Alex really helpful. Ill hold out until the end of the week and out an order in for it all