hi guys please help need advice on filters

[Noel]

I got my gear off a guy second hand 2 years ago, it has been brilliant producing .000 for the last two years. I tested it the other day and it has gone up to .002 which has been fine but I am now looking to replace the Carbon and Sediment filters. Problem is as I got them second hand so i'm not sure where to get the correct filters so any advice will be appreciated that will fit the 2 big blue housing housing. Are filters housing specific or are they interchangeable?

Also are filters graded?

View attachment 8163

 

[spruce]

The first filter in the clear housing looks like a Jumbo 10" wound sediment filter. These comes in different particle micron rating, ie 5 to 100.

The second and third housing appear to be 10" Jumbo prefilters. I'm guessing that 1 is a carbon block and the second a GAC filter. The Jumbo filters are 4.5" diamt and 9.75" in length.

You can replace the 2 Jumbo carbon prefilters with 1 x Fiberdyne from Gardiners and leave the second filter empty.

JUMBO 10" Fibredyne CFB PLUS Sediment/Carbon Pre-Filter - Sediment & Carbon Filters - Water Treatment - Pure Water Systems - All Products Gardiner Pole Systems

If your water is pretty sediment clear then you can do away with the sediment filter as well. We can't so we also use a 5 micron sediment filter.

I certainly wouldn't waste time with a larger micron sediment prefilter as the Fiberdyne is 5 microns.

Not sure what you mean by graded. The Fiberdyne c/b filters have a large service life capacity ( 94600 litres = pure + waste.) Other filters have a shorter service life.

I'm surprised that you have got away with not changing prefilters since you bought your system. Once the service life of the carbon block is used up then chlorine passes to the r/o membrane/s and destroys them.

There are 2 of us using water from our r/o. We have to replace prefilters about every 3 months on average.

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[Noel]

Great advice thank you! I was getting stressed about where to find the right filter...advice much appreciated.

Yea probably lasted because I was on 2 days a week :S Got motivated for canvasing so going up to 3-4 days a week now.. the hard life!

What PPM should the water be after the Filters and before the RO?

What should the PPM be after the RO before the De-ionising vessel?

The image below shows the RO, on the invoice it says HF4 40/40 ultra low pressure.

What is the difference between HF4 and HF5...which membrane should I get?

View attachment 8166

 

[spruce]

Great advice thank you! I was getting stressed about where to find the right filter...advice much appreciated.
Yea probably lasted because I was on 2 days a week /emoticons/wacko.png Got motivated for canvasing so going up to 3-4 days a week now.. the hard life!

What PPM should the water be after the Filters and before the RO?

What should the PPM be after the RO before the De-ionising vessel?

The image below shows the RO, on the invoice it says HF4 40/40 ultra low pressure.

What is the difference between HF4 and HF5...which membrane should I get?

View attachment 11519

What PPM should the water be after the Filters and before the RO?

The same as your tap water. The prefilters won't make much difference if anything the the ppm of the water. The only thing the prefilters remove is chlorine as that destroys the r/o membrane.

What should the PPM be after the RO before the De-ionising vessel?

What you are asking is how efficient should a membrane be at removing dissolved solids. No membrane will remove all the dissolved solids in the water so won't work at 100% efficiency.

Most specs will show a rejection rate of between 97% to 99% as being normal under ideal conditions - water temperature, pressure etc when a membrane is new. But what is normal for 1 window cleaner may not be normal for another.

The less efficient a membrane becomes with age, the more resin it will take to 'polish' the pure off. In the early days I was given the advice that you don't want to let your membranes drop below 94%, but at the end of the day it's your decision when to change it and will be governed by other factors.

Our tap water fluctuates between 99 and 126 ppm. The tds of the pure out of the r/o is between 1 and 2. My membrane consistently runs at an efficiency of 98.5%. My membrane is 4 years old on the 12th of July.

At 94% my rejection rate will be 6ppm from the r/o. As I currently put my water through di it means that I would be using 3 times the amount of resin than I'm using now. While that sounds dramatic, cost wise it isn't. In my case I'm replacing my resin in my di vessel once a year. If I let the tds rise to 6 ppm then I will need to replace that resin every 4 months with the amount of water we use. So its cheaper to buy resin than a new membrane. (I would replace the membrane as I hate the job of changing resin in the di vessel.) I would also need to be more studious at watching the tds after di at 6ppm. I can see slight spotting at 6 in low sunlight from the inside so wouldn't dare clean windows with that water.

If the tap water tds was 300 then it becomes a different story. At 94% your pure water from the r/o would have a tds of 18. That would mean I would be changing the resin much more often and over a year the extra cost of resin would come close to paying for a new membrane.

.... on the invoice it says HF4 40/40 ultra low pressure.


What is the difference between HF4 and HF5...which membrane should I get?

There is one supplier that lists virtually all the membranes they sell as ultra low pressure membranes. Gardiners website describes the membranes correctly as HF4 for low pressure and HF5 as ultra low pressure.

An HF5 membrane will run at a slightly lower water pressure than an HF4 will. Gardiner's advise that the optimum pressure for an HF5 membrane is between 50 and 100psi and the HF4 as 80 to 105psi.

I was once advised by a large wfp supplier that at 40psi water pressure (ours at home at the time) both these membranes would perform the same. I wasn't totally comfortable with their advice so I bought the slightly more expensive HF5.

Our water pressure has been raised to 50 psi now, but I'm concerned as there are plans to build 149 houses bordering our estate which could change things.

If you have plans to add a booster pump to your setup then you could well consider an HF4 membrane.

Presently at 50 psi the HF5 membrane produces 2 lpm of pure and 2 lpm waste. That's plenty for our needs. The r/o kicks in when about 200 litres of water has been taken from our ibc storage tank and switches off when full so needs no 'supervision.'

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