Changing RO unit prefilters | The Aquarium Solution

Changing RO unit prefilters

Question:

I have the D-D Reverse Osmosis Unit. It is about 2 years old. It was not used frequently for a while, and none of the filters have been replaced. I know that you recommend replacing the membrane every 2-3 years, and the filters more often than that.

As the filters age, I assume that they get less effective progressively.
What I mean by this that you won't have a situation where they work today but not tomorrow, but rather a steady deterioration. Does the quality of the water get worse as the filters age or is there just a reduced volume of water produced?

I am mostly concerned about fluoride in the water, therefore I am concerned about the membrane. I use the unit for drinking water due to the local water supply being subject to fluoridation. So as the membrane ages, should I be concerned that there might be fluoride in my water, or rather that the rate of water being produced is slower? Why does the membrane need to be replaced, is it because it is being blocked and can't process water quickly enough, or because it can't remove the intended chemicals?

I notice that the flow is slowly now than when I got it, but it is not too slow yet, and obviously I want to go the longest time possible without having to replace the membrane. As fluoride is my main concern, I would be willing to using the membrane without the prefilters, especially since they are much further past their ideal replacement date

Sorry for such a long winded question,

Gregory.

Answer:

Hi Gregory

Its is important that the sediment and carbon pre filters are replaced every
6 months or so. The pre filter catches sediment down to 5 microns, as the
sediment filter
ages it can become clogged and sediment can find its way into the pores of
the RO membrane. This will eventually ruin the membrane and reduce the
effluent quality.
If you view the filter through the clear casing you will notice it will
become brown with sediment over time and this is when to change it out and
at the latest
every 6 months.

The carbon filter removes chlorine from the tap water pre membrane, chlorine
can damage the membrane if allowed to come into contact with it so again
this needs
to be changed out every six months or so.

You shouldn't run the unit without these as the membrane will quickly become
fouled with sediment and eventually become damaged by chlorine allowing
unwanted
ions through the filter.

The best way to test the quality of your RO effluent water is by using a TDS
meter, this will give you an indicator to the condition of your membrane.
Also if the membrane
was allowed to dry out when it wasn't in use it should be replaced as this
will have damaged the membrane as they must be kept wet.

More info on TDS and general RO unit installation can be found in the
articles below.

http://www.theaquariumsolution.com/tds-what-does-it-mean-and-why-should-i-test

http://www.theaquariumsolution.com/installing-d-d-reverse-osmosis-unit

All replacement pre filters and TDS meter can be purchased from your local
D-D retailer, if you have any problem locating a local dealer please mail
our spares dept
at spares@theaquariumsolution.com for parts.

hope this helps Tony