[Dazzler3370]

 Not exactly an exciting topic for a Sunday but I would like to know
I currently have 3 pre filters,
But I've heard that you only require 2.
What is the correct requirement
Any advice gents,
Also how often do you change them...??
Cheers
Dazzler

[Spruce]

Not exactly an exciting topic for a Sunday but I would like to know
I currently have 3 pre filters,
But I've heard that you only require 2.
What is the correct requirement
Any advice gents,
Also how often do you change them...??
Cheers
Dazzler

Usually an r/o sold with 3 prefilters is the supplier covering all sales bases and not window cleaning specific.

Personally, we need a sediment and a carbon block, so that's 2. We don't need a GAC 3rd prefilter to make the water taste better as we are using it for window cleaning. We also polish our water off with resin which isn't FDA approved for drinking water as far as I know.  (An Australian website suggests deionised water through Tulsion MB115 resin is fit to use for reefkeeping hobbyists.)

We use Spectrum sediment filters and Fiberdyne carbon block and adhere to the manufacturers replacement cycle for the carbon block filter.

There will be some who argue that adhering to this change cycle isn't necessary as often we don't have any chlorine in our tap water most of the time. I'm not disagreeing with this, but we have no way of actually knowing when chlorine is present and how much when it is.

For us with 20"  prefilters, I change the C/B filter every 77,000 liters which is around 4 months use. This 77k is the water that passed through the prefilters and r/o membrane. Its both the waste and the pure.

Our water at times is very sediment laden so we have to use a sediment filter to protect the Fiberdyne C/B filter from clogging up. If our water was sediment free then we wouldn't need the sediment filter. The C/B filter would suffice as a combo filter for the duration of its service life.

[Dazzler3370]

Thanks Spruce 👍

[NWH]

I need to change mine haven’t changed them for about 4-5 months,I use carbon and sediment and an HF5 RO I’m still getting 003-004 with little flushing.

[Dry Clean]

I wouldn't argue that we don't need pre filters its just that some people don't actually know why it is we use them, they have only one use which is to insure the money we have put into the membrane by protecting it, smell and taste your water, if it seems high in chlorine then you may need to change them more often, just don't fall for the overpriced gimmick membranes with fancy names as these will soon outweigh any potential saving.
There's nothing wrong with having two carbon filters, it just means you will get double the time before needing to change them, but instead of the more expensive GAC use a normal block.

[Dry Clean]

I need to change mine haven’t changed them for about 4-5 months,I use carbon and sediment and an HF5 RO I’m still getting 003-004 with little flushing.

Similar, mine usually go green and slow down after around six months, other than that I would leave them longer.

[NWH]

Yeah when I take mine out they have gone green also,I went through a spell a couple of years ago they needed changing every 2-3 weeks due to a huge amount of rain we had.
I know we’ve had a lot of rain this past couple of months but it hasn’t effected it the same this time around,lots of rain in the ground means more sediment apparently therefore the sediment filter is spent a lot lot quicker.
When I’ve transferred into tank a couple of times a week I always dip the meter in the tank once it rises to around 7-8 I’ll change the pre filters only this time or the last couple of times it’s stayed on 3/4 for ages.

[NWH]

I flush my RO for around half an hour hardly at all mines lasted years.

[nathankaye]

Sediment filter and then i use a fibredyne filter and then RO.
Fibredyne can be used as a sediment and carbon filter in one and some choose to use this and then another carbon block.  However i would not disregard a seperate sediment filter at all

[mufcglen]

I used to use sediment and carbon but last year or so I’ve been using just the single fibredyne that does both and its supposed to last longer,i got sick of changing the sediment fairly often as recommended although it looked fine taking it out.
I change mine every 6 months and ro working fine producing 2-3ppm nearly two years old now

[Steve Carpenter Window Cleaning]

Hi

My 4040 ro goes from 25ppm to 100ppm in about 6 months. I change the 3 prefilters every few weeks and I have an automatic flush set for 5mins every 4 hrs.

Why does my tds go so high? 

[Spruce]

Hi

My 4040 ro goes from 25ppm to 100ppm in about 6 months. I change the 3 prefilters every few weeks and I have an automatic flush set for 5mins every 4 hrs.

Why does my tds go so high?

You need to tell us what your water pressure is;
The amount of LPM of water flow you have at your tap;
What membrane you are using;
What your input tap water tds is;
and what your waste to pure ratio is when you are processing water.