100 GPD Portable RO/DI review

[teebs]

Just got my portable 100GPD RO/DI unit recently but decided to reconfigure it into two sets, a sediment filter + carbon filter & faucet adaptor for drinking water and the sediment, carbon, RO and DI unit for aquarium use only.

Reason for this is that RO units will have waste water that is usually ard the ratio of 2L+ of waste water for every 1L of RO/DI water produced.

Here is the RO/DI unit that I got from USA.

The 100GPD RO Membrane made in USA.

Current setup of my RO/DI in my toilet. Using the existing Crystal Pro unit to hook up to my water supply as I did not get the hose adaptor from the supplier. Couldn't find the correct size adaptor at hardware stores ard my area. Currently setup as follows: Sediment=> carbon> RO membrane=> DI=> outlet.

I'm using the carbon catridge stage of the Crystal Pro unit to connect my RO unit. Basically I took out the carbon catridge so the filter catridge is empty, then I connect the inlet of the RO/DI unit to the back connector of the Crystal Pro.

[teebs]

Now for the TDS readings:

Tap Water TDS reading: 187ppm

TDS Reading after the carbon stage of the RO/DI filter. This is the pre RO stage: 187ppm

TDS Reading after the RO stage before the DI stage: 18ppm [From the reading, the RO membrane has a 90% TDS rejection rate]

TDS Reading after the DI stage: 0ppm

TDS reading of the waste water produced by the RO: 294ppm

[jackywongto]

so fast arrive already arh.....

you stuffs always so power wan.... hehe....

now you dun have to worry about your tapwater 165 ppm TDS liao.

[LaW]

nice work done Peter

btw, i was wondering how much time needed to produce 1liter, though it said to make 100gpd, sometimes it should be an estimation.

[jackywongto]

think i see another bulk order in the making ...............

you have another title now - BO king !

[teebs]

so fast arrive already arh.....

you stuffs always so power wan.... hehe....

now you dun have to worry about your tapwater 165 ppm TDS liao.

My tap water is 187ppm just now. In the morning when i did my first batch of RO/DI water, my tap water was 257ppm...

[teebs]

nice work done Peter

btw, i was wondering how much time needed to produce 1liter, though it said to make 100gpd, sometimes it should be an estimation.

Later, I will use a 1.5L bottle to time how long it take to fill it up and how many litres of waste water is produced. Actually the rejection rate was slightly lower than expected. According to the supplier, the 100GPD membrane has a rejection rate of 95% at 60psi pressure. So it seems that the HDB supply is less than that.

[jackywongto]

My tap water is 187ppm just now. In the morning when i did my first batch of RO/DI water, my tap water was 257ppm...

so it fluctuates through the day.

theory: if the TDS is always higher in the day, then it makes sense for us to collect water for WC in the evening

[teebs]

think i see another bulk order in the making ...............

you have another title now - BO king !

Bulk order for this will be quite difficult as it is expensive. Shipping cost is also very high.

[teebs]

so it fluctuates through the day.

theory: if the TDS is always higher in the day, then it makes sense for us to collect water for WC in the evening

I don't think it happens thia way...

Basically it depends on the treated water that is being pumped to our homes.

[kanegan]

Hi bro,

Just curious. Are you able to calculate how much it cost you to produce 1 litre of 0 TDS water? Assuming the filter will need replacement after X litres produced.

[teebs]

Ok, I just took the time for the RO/DI unit to fill up a 1.5L bottle of 0 TDS water. According to my watch, it took 8 minutes to fill up the 1.5L bottle.

The waste water produced is this much:

Using a measuring container to measure the amount of waste water produced gave approx 2.7L.

So 1.8L of waste water produced for every 1L of 0 TDS water produced.

[teebs]

Hi bro,

Just curious. Are you able to calculate how much it cost you to produce 1 litre of 0 TDS water? Assuming the filter will need replacement after X litres produced.

According to the supplier, the DI catridge is able to produce approx 500 gallons of 0 ppm water before it needs to be changed.

Anyway, the set I got comes with an extra DI catridge, 1.5lbs of MB400 resin good for 4 refills and 1 extra sediment and carbon filter. Total effectively is 6 DI catridges and refills.

Based on my total set cost of ard $400,

Max volume of 0ppm water that can be produced = 3,000 gallons = 11,400 L

Cost of producing 1L of 0 ppm water at max volume: $0.035

Cost of producing 1L of 0ppm water assuming 500L produced: $0.80

Cost of producing 1L of 0ppm water assuming 1,000L produced: $0.40

Cost of producing 1L of 0ppm water assuming 2,000L produced: $0.20

Cost of producing 1L of 0ppm water assuming 4,000L produced: $0.10

Cheapest distilled water: NTUC Pure water @ $1.35 for 4.5L => $0.30/L

Crystal Pro unit with 5 refill sets: $198 + $300 = $498.

According to my usage 2 Crystal Pro DI catridges can produce ard 240L of 0ppm water before it needs to be changed.

Cost of producing 1L of 0ppm water using Crystal Pro = $498/(240x6) = $0.35

[desideria]

Wow Peter... THANKS for this review.. i'm considering seriuosly of getting an RO unit too... I"d be asking RB what RO Unit they can get for me and the price... especially since I"m concerned whether the replacement catridges are easily available.. wouldn't want to buy something and end up replacement parts become a pain. ;P

[kanegan]

According to the supplier, the DI catridge is able to produce approx 500 gallons of 0 ppm water before it needs to be changed.

Anyway, the set I got comes with an extra DI catridge, 1.5lbs of MB400 resin good for 4 refills and 1 extra sediment and carbon filter. Total effectively is 6 DI catridges and refills.

Based on my total set cost of ard $400,

Max volume of 0ppm water that can be produced = 3,000 gallons = 11,400 L

Cost of producing 1L of 0 ppm water at max volume: $0.035

Cost of producing 1L of 0ppm water assuming 500L produced: $0.80

Cost of producing 1L of 0ppm water assuming 1,000L produced: $0.40

Cost of producing 1L of 0ppm water assuming 2,000L produced: $0.20

Cost of producing 1L of 0ppm water assuming 4,000L produced: $0.10

Cheapest distilled water: NTUC Pure water @ $1.35 for 4.5L => $0.30/L

Crystal Pro unit with 5 refill sets: $198 + $300 = $498.

According to my usage 2 Crystal Pro DI catridges can produce ard 240L of 0ppm water before it needs to be changed.

Cost of producing 1L of 0ppm water using Crystal Pro = $498/(240x6) = $0.35

Wow! Thanks for the detailed calculations. So it still makes sense for your system assuming the cost of the tap water (including waste water) is insignificant. But using Crystal Pro will be ... Is NTUE Pure water really TDS 0? I don't think so right?

Great review!

[teebs]

Wow Peter... THANKS for this review.. i'm considering seriuosly of getting an RO unit too... I"d be asking RB what RO Unit they can get for me and the price... especially since I"m concerned whether the replacement catridges are easily available.. wouldn't want to buy something and end up replacement parts become a pain. ;P

For RO units, you do not need to worry about replacement catridges. The RO membrane is rated for 5,000 gallons, the sediment and carbon filters are rated for 1,500 to 2,500 gallons. The DI catridge is refillable so you only need to get the replacement DI resins.

If you are worried about replacement catridges, you can get the full size RO unit and not this portable unit. The full size units uses standard 10 inch catridges which you can get in Singapore easily.

I believe the RO units in Singapore typically do not come with DI catridges. DI catridges is usually an add on so it will cost more. Also when buying RO catridges take note whether the membrane is 50, 75, 100 or 150 GPD. There is a lot of difference in the amount of water it can produce per day and also the cost of the RO unit.

[teebs]

Wow! Thanks for the detailed calculations. So it still makes sense for your system assuming the cost of the tap water (including waste water) is insignificant. But using Crystal Pro will be ... Is NTUE Pure water really TDS 0? I don't think so right?

Great review!

TDS reading of NTUC Pure water is ard 1-3ppm. I measured ard 15 bottles previously and this is the TDS range I am getting.

[LaW]

Ok, I just took the time for the RO/DI unit to fill up a 1.5L bottle of 0 TDS water. According to my watch, it took 8 minutes to fill up the 1.5L bottle.

The waste water produced is this much:

Using a measuring container to measure the amount of waste water produced gave approx 2.7L.

So 1.8L of waste water produced for every 1L of 0 TDS water produced.

thanks Peter. so i think one day that will make 270 liter. the differenct from 100gpd could be due to pressure being lower than the recommended. what do u think?

[teebs]

thanks Peter. so i think one day that will make 270 liter. the differenct from 100gpd could be due to pressure being lower than the recommended. what do u think?

The working pressure for my unit is between 35 to 65 psi. Judging from the rejection rate of the RO membrane I am getting 90% compared to the optimal range of ard 95%.

Obviously the rating of the RO membrane is based on 60-65psi pressure so from the readings I am getting, I believe the water pressure in my home is probably ard 45-50 psi only. Another issue is that the water passes through the first filter catridge of my crystal pro before entering my RO/DI unit so this might cause some drop in the water pressure also.

[LaW]

The working pressure for my unit is between 35 to 65 psi. Judging from the rejection rate of the RO membrane I am getting 90% compared to the optimal range of ard 95%.

Obviously the rating of the RO membrane is based on 60-65psi pressure so from the readings I am getting, I believe the water pressure in my home is probably ard 45-50 psi only. Another issue is that the water passes through the first filter catridge of my crystal pro before entering my RO/DI unit so this might cause some drop in the water pressure also.

sound logical. do let me know if you are getting a pressure guage. i want to get one as well.

thanks Peter.

[teebs]

sound logical. do let me know if you are getting a pressure guage. i want to get one as well.

thanks Peter.

Let me check if I can get the pressure gauge locally first.

[teebs]

For those interested in getting replacement inline replacement catridges, you can check out the local website (AiFrex) below:

http://sgwaterpurifier.com/index.php?act=viewCat&catId=9

They also have the 50GPD RO system. However, you will need to add the DI stage yourself as it does not come with it:

http://sgwaterpurifier.com/index.php?act=viewProd&productId=131