Hi m8,
Could you give me some info on post number 10
http://www.cleanitup.co.uk/smf/index.php?topic=203979.0
Just wondered if you could clarify the difference between the wrap and block and their purpose regarding reducing tds if any or merely lasting longer ( blocks)
cheers Fieldsy
Hi Fieldsy,
I honestly don't know the answer.
The first time I heard the carbon filter being called a carbon wrap filter was your post and the link.
I have always known it as a carbon block or just carbon filter. Most other cleaners also call it a carbon or carbon block prefilter. If I look at the pictures, both filters look exactly the same.
What interests me though is the length of their service life. I can vouch for the Fiberdyne carbon block filter as I have used it in my 4040 system for 4 years and the membrane is working just as well as it did when I first put it in. I don't have a chlorine test kit so I can test my carbon block filters to see if they are working or not. TBH I couldn't be bothered. Its far to complicated removing water pipes to get a test sample. I just change them when the manufacturer tells me to.
What I don't like is the use of "the reduction of chlorine" rather than removal. Being cynical, I see that as a get out clause by the manufacturers. What does chlorine reduction mean? How much is left? etc.
The very first carbon prefilter I used was a 1 micron unit with was good for 150,000+ liters if my memory serves me and was £38.00 + VAT. But it blocked up within a few months and had to be discarded.
Replacing prefilters will do very little for the reduction of your tap water tds. In fact, it will probably be exactly the same. All the carbon block does is remove chlorine from the water as chlorine and r/o membranes aren't good bedfellows. Chlorine also dissipates. We had to dose our swimming pool in South Africa every evening to sanitise the water. Once the morning sun rose it didn't last long before it was gone, perhaps less than a couple of hours.
Doug put up a post a while back about chlorine. He said that the further you get from the dosing point the weaker the concentration of chlorine. So it could be that those Fiberdyne filters will last me twice as long.
I would imagine the manufacturers of these things will spec the filter as the highest chlorine content your water could have to be safe for drinking. So if I follow the manufacturers instructions I feel I'm ok.
However, as SeanK posts, it is also a balance between spending lots on filters to save a little on replacement membranes. He gets away with replacing his every 6 months.
Edited:
The Spectrum prefilter you linked to is a much better bet than what you are using IMHO.
http://waterfilters.sterner.co.uk/index.php?route=product/product&path=74_316_229&product_id=645Using that will work out similar cost wise to the fiberdyne I'm currently using, although I would have the convenience of not changing it as often. But I would still have to disconnect the prefilters and drain the system down to change the sediment prefilter.