RO System Pre-Filter Sequence

Hi everyone!

What is the best siquence for pre-filters. I have 300gpd system (3x100gpd) and 3 pre filters. Im in ro market but i dont realy know which is the best to be honest, its better to ask experts

I have seen 2 sets:

1. 5 Micron sediment+ carbon block+ 20 Micron sediment
2. 5 Micron sediment+ Carbon block+ activated carbon


Wich is better and in what siquence ?


Thank you!

 

The first one is kinda pointless. A 20 micron filter is bigger than a 5 micron, and wouldn't have anything left to catch if it's placed after a 5 micron.

Beyond that, the carbon has a micron rating too, which is important. There's also the issue of 5 micron being relatively gigantic holes compared to units I've seen.

 

Look for a unit with something along the following sequence:

1st - 1 Micron Prefilter
2nd - Activated or block carbon with smallest micron rating you can find
3rd - RO Membrane
4th - DI resin

There are models that have a gazillion stages. If you buy quality components and maintain them/replace when necessary, you will still get good to excellent results with a 4 stage system.

Good luck!!

 

I have seen 1micron sediment filter. I think i will go for

1 Micron sediment
Activated carbon 5 Micron i could not find les that 5
+ DI

 

Yeah I dont think there are too many carbon units on the market less than 5 microns. Your prefilter will get all the particles out and the 5 micron prejudice of the carbon filter will ensure it will have good flow going to the RO membrane.

 

Oh and something else to consider if you are putting this system together is to look for housings with John Guest Speedfittings. They are ultra easy to work with and are very reliable.

 

Spectrapure's cheapest is 5 micron for carbon. The others are 1 and 0.5.

Their sediment filters are 1 micron and under, at .5 and .2.

I mean, look for yourself.

 

Here's the sequence of the Typhoon RO/DI unit:
1. ten micron sediment filter for your first stage.
2. five micron carbon block, acid washed filter for the second stage.
3. the third stage is a one micron carbon filter or a sediment filter if you have well water.

The rationale, as blackraven aluded to above--is to never put a filter with a larger micron rating after a smaller one. It's the same idea as using a coffee filter, followed by a colander.

 

Thank alot !

 

The Typhoon is old technology and should be changed to their optional sizes.
ALWAYS use a prefilter that is no larger than the particles you want to plug or foul the pores in your carbon block. Personally I use a 0.2 micron absolute rated prefilter which is pleated and has 10x the surface area of a normal spun poly filter with less pressure drop or resistance, a single 0.5 micron 20,000 gallon carbon block since it is being well protected from fouling by the prefilter then the RO membrane and the DI.

Many vendors still use larger micron size, nominal rated prefilters then add two carbon blocks so one is acting as the prefilter and rendering it useless as a carbon filter so only thge second one actually adsorbs chlorine and VOCs. This goes back to the olden days when filter technology was not what it is today for both prefilter and carbons. Modern carbon is amazing if and only if the pores are kept clean. I once subscribed to the old Typhoon configuration myself as it was the way we did things in the water treatment plant I supervised. I have since learned much more and kept up with the times.