RO Unit Questions

Galibore

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Hi Guys,

I was wondering, for how long at a time do you guys flush your RO units for and how often.

What normally goes first on a 4 stage? In other words, what should I look at replacing first?

My TDS reading has always been zero. Now it reads 2. My unit is probably about 10 months old and I haven't replaced any of the inserts yet. It's got the sediment filter, carbon block, RO membrane and DI resin.
 

Mike

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Change the DI resin, i find that is usually first to go, and by the readings it looks like it has gone, how long all the filters last is down to how good the water is to start with, it the TDS input is high it will wear down the filters quicker, but i'd look to be replacing all the filters annually anyway.
 
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i change my di resin when it turns yellow, and then i change my sediment filter when readings go above 0 and if it stays at 2 change the carbon( the membrane is done last)

you got a new tank or what?
 
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RO DI prefilter maintenance interval

Good to see you're around !

Use below as a working guide.
I have used RO, in PE, CT, JNB.

Flush before EACH use. About 5minutes.
Especially if RO used less than 2/week.


Change DI as soon as it's exhausted according to colour-indicator .
IF you DON'T have colour indicator resin, then testing is in order.
DI resin volume treatment capacity is lowest, therefore gets used up quickest.

THEN sediment
THEN Carbon Block Resin
LAST 2 ARE BEST CHANGED SIMULTANEOUSLY.

QUICK TIP!!
Flush membrane.
Disconnect DI
test TDS of RO, before DI
Then you have idea of WHAT level tds is removed by your DI, as is.

Workout Tapwater RAW tds
KNOW that good RO removes min 90-95% of THAT.
DI polishes remainder down to 95-99% IF REQUIRED

eg)
My CT tap is 60ppm tds
RO yields 2-6ppm [Tested: NO phosphate, nitrate, silicate]
DI makes it 0-1ppm

I am perfectly happy with using my RO, and don't bother with DI.
BUT, it's connected, ready to be charged and brought online within minutes.

All depends on how bad raw-feed water is ....

I use it as long as under 10ppm, replace ALL prefilters every 2-3months or sooner. With regular, weekly testing to maintain margin of safety

According to needs, I produce 500 - 3000L a week .


You are FAR from membrane replacement

Hope this helps abit, at least.



Hi Guys,

I was wondering, for how long at a time do you guys flush your RO units for and how often.

What normally goes first on a 4 stage? In other words, what should I look at replacing first?

My TDS reading has always been zero. Now it reads 2. My unit is probably about 10 months old and I haven't replaced any of the inserts yet. It's got the sediment filter, carbon block, RO membrane and DI resin.
 
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It's so easy to to check the state of your sediment filter. I replace mine as soon as it gets a shade of brown.
 
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might be a stupid question but how to you "Flush membrane"
and how much is a tds meter and where do you get them?
 
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might be a stupid question but how to you "Flush membrane"
and how much is a tds meter and where do you get them?
If you have it permanently connected, not really an issue. Flushing the membrane is basically running water through the unit for 30 minutes or so.

Get from LFS or sponsors
 
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i have it permanently connected and i use it 2 a week. so should i not worry about it.
how much do they normally go for?
 
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i have it permanently connected and i use it 2 a week. so should i not worry about it.
how much do they normally go for?
I have been running my RO for 12 months now at Zero TDS and have not had to replace membrane or filters.

Replacement is dependant on usage and the quality of the tap water.

That is why the TDS meter is important for monitoring purposes
 

Tobes

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i have it permanently connected and i use it 2 a week. so should i not worry about it.
how much do they normally go for?
Bought mine for R300 at Eco-Aquatics, that was over a year ago, might be double now :p
 

Tobes

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I have been running my RO for 12 months now at Zero TDS and have not had to replace membrane or filters.

Replacement is dependant on usage and the quality of the tap water.

That is why the TDS meter is important for monitoring purposes
Mine as well, been running 13 months and still tests 0. Tested my tap water and TDS = 40 :slayer:
 

dallasg

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i just bought my RO unit now, hopefully get it on monday/tuesday
 
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THEN sediment
THEN Carbon Block Resin
LAST 2 ARE BEST CHANGED SIMULTANEOUSLY.

... All depends on how bad raw-feed water is ....
Good advice there from Obi-Wan (Hi Obi-Wan, long time to hear :wave2:)

Most important variable is, of course, the quality of the input water.

Here in Bloemfontein our water is VERY dirty (sediment/mud), and I need to change my first sediment pre-filter (I use 5 micron) every 2 months or so (sometimes even more frequent...)

The carbon block pre-filter's main purpose is to remove chlorine (added by the municipality to "sterilize" the water), as this attack the actual RO membrane. Depending on how diligent your municipal water treatment people are, you might need to replace this pre-filter as often as every 6 months, or as long as once every year. As the carbon block pre-filter is substantially cheaper than the actual RO membrane, I would advise to rather be safe than sorry, and replace it every 6 months.

As a point of interest, because of Bloem's atrocious water quality, I have 4 pre-filters ahead of the RO membrane: from the municipal water supply side there is firstly the 5 micron sediment filter, then a GAC (granular activated carbon, same as we use in our aquaria), then the carbon block, and lastly a 1 micron sediment filter. In general, I replace the first two every 2 months, and the last two every 6 months.

Hennie
 

dallasg

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come to sandton, great water ahaha
 

dallasg

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touche' , but it aint private, its our wonderful rand water board...

if i may ask hennie, your profession? engineering of some sort? coz ur setups are wonderful, if i could afford the shipping your 1m cube would look good in the center of my lounge
 
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if i may ask hennie, your profession? engineering of some sort?
Yup, you guessed it :thumbup:

if i could afford the shipping your 1m cube would look good in the center of my lounge
Perhaps you've got me confused with someone else - my tank is a 1.8 x 0.7 x 0.7, and not a cube (wish I had space for a decent size cube, though...)

Hennie
 

dallasg

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my bad i did...
nice tank, but a bitch to ship unless stripped
 

dallasg

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a quick Q, i have a waterboy RO unit, reefmaster evolution, should the waste produce more water than the RO outlet? also isnt the waste water good for anything seems to be a "waste" of water.. thanks
 

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