[ben M]

any good?

http://www.ebay.co.uk/itm/RO-Reverse-Osmosis-10-Carbon-Block-Sediment-Filter-/230839965768?pt=UK_Pet_Supplies_Fish&hash=item35bf225848

thanks.

[Spruce]

Hi Ben.

You need the best carbon filters you can buy. You have a 10" carbon block filter having to declorinate all the water that's passing though your 4040. This is a tall ask at the best of times. I see this co on ebays says the filters are good for 2500 gallons (+- 11250 litres).

So if you have your r/o set for 50/50 waste to pure, then the carbon block would do you 5600 litres of pure. If you use 350 litres of pure a day, that means you need to replace your filters every 16 working days, so about every 3 weeks.

I would speak to June at GAPS water and get her advice. I would probably consider removing the sediment filter and replacing that with a carbon block and then putting a CAG carbon filter in the second filter housing. These filters are 'cheap' when compared to the cost of a replacement r/o membrane. Remember, chlorine eats membranes, so once the carbon block becomes useless, you are putting your membrane at risk.

[ben M]

Thanks Spruce, do you use yourself a carbon block and then a CAG carbon filter in the second filter housing?

regards.

ben

[Spruce]

No Ben,

I have a 450 GPD Roman and I use a sediment filter and CAG and that has worked for me over the years.

Your problem is that your 10" filter has to deal with many time more volume of water being filtered through it at one time. I may use more water than you, but my filtration unit works slowly whereas yours works much faster and so the carbon filter has to be more efficient.

[Smart Carpet]

I wouldn't skip the sediment filter! have you seen the stuff it filters out?

I agree ask June at GAPS as to best way to go, she advised to me to use sediment and carbon block (IIRC)

The GAC filters (Granular Activated Carbon) don't last as long, and the granules can cause channeling where the water finds an easy route through the granules.  (though you can use a GAC as well as a block filter and sediment for a 'belt and braces' approach, just change the GAC a lot more regularly. (300 gallons)


Having said all of that, I used to run a 4040 RO with only softener resin as prefilter, that rarely got recharged with salt, and the membrane was producing water at around 17ppm for years.

However, new membrane (now with pre filters fitted and no softener) outputs at 2ppm.

[Spruce]

I wouldn't skip the sediment filter! have you seen the stuff it filters out?

I agree ask June at GAPS as to best way to go, she advised to me to use sediment and carbon block (IIRC)

The GAC filters (Granular Activated Carbon) don't last as long, and the granules can cause channeling where the water finds an easy route through the granules.  (though you can use a GAC as well as a block filter and sediment for a 'belt and braces' approach, just change the GAC a lot more regularly. (300 gallons)


Having said all of that, I used to run a 4040 RO with only softener resin as prefilter, that rarely got recharged with salt, and the membrane was producing water at around 17ppm for years.

However, new membrane (now with pre filters fitted and no softener) outputs at 2ppm.

Thanks for the correction  - GAC not CAG 

I think is was Vyair that suggested the double carbon filters as the carbon block is also 5 micron so will act as a sediment filter as well..

Personally, I change mine regularily and I haven't had any problems with my 3 membrane R/O, but the experts in this field tell us that chlorine is a membrane killer. TBH sometimes my GAC filter has been in much longer than 11250 litres without any effect on the membranes - they are over 6 years old now.

Spruce

[Smart Carpet]

 

I suppose the advantage of a spun fibre sediment filter is that you can see the colour change as it becomes saturated with 'dirt'..

I think you're right Spruce, regularly changing the filters is important.

[Smart Carpet]

I changed my filters today for a set of filters from eBay (same as link shown above).

Look how dirty they get in 5 months!  (Will change sooner next time!) 

[lozsing]

I change every 12 weeks

[SB Cleaning]

I change every 12 weeks

Me Too

I buy my filters from Vyair