RO Waste Ratio ??

[ash9965]

ok So I just bought a used ( Triton ) RO system so Filters supposingly only had a few months of use but had been sitting around for a bit so I flushed them out and decided I would go ahead start using them . So 3 questions as long as the TDS #s out put is good am I ok with using them even though they have been sitting for a while. Also what is the normal waste water to fresh out put ratio before I should start looking at changing the filters ( Kit 3 Pieces) finally the new filters I ordered online from BRS look nothing like the 3 currently on the unit so how do you know what order to put the new filters? Thanks in advance. Note even though its working it seems the waste output is much higher than clean output.

 

[Opus]

Not knowing what the prefilters had been thru, I personally would change them. They have no effect on TDS so you could be getting good TDS numbers after the RO membrane but the prefilters could be letting thru harmful chemicals that could destroy the RO membrane. The prefilters are there to protect the membrane. You are looking for 2 or 3 waste to 1 filtered ratio. As for the filters, you want the sediment filter first then the carbon filter 2nd. Then to the RO membrane and then the DI filter. I would expect the from BRS to be labeled.

 

[ash9965]

mine has 2 membranes then the 3 filter kit

 

[Opus]

Check out the Triton website, they have the manual online and shows you what is in each canister. Also, since you have a dual membrane, I believe a 4 to 1 ratio is recommended for those.

 

[AZDesertRat]

Sediment and carbon filters have nothing to do with TDS, they are there to remove large suspended solids, silt, particulates, colloidal materials and chlorine. The two best indicators of sediment and carbon condition are headloss or pressure drop between the tap and the pressure gauge at the RO membrane and chlorine breakthru measured with a low range chlorine test kit.

The rejection rate or removal efficiency tells you the RO membrane condition. This is a calculation using the tap TDS and the RO only TDS. For example lets say you have the national average tap TDS of 250 and you are measuring a TDS of 10 from the RO membrane before the DI filter. 250-10=240, 240/250=0.96, 0.96x100 =96% rejection rate, which would be borderline ready for replacement to me. For every 2% your rejection rate drops you cut your DI life in half so having a more efficient membrane pays for itself in saved resin.

The industry standard waste ratio is around 4:1. If you have softened water and lower than normal TDS you can probably get by with 3:1 but I wouldn't go any lower than that with a dual membrane system or you will be buying membranes frequently since they are not being sufficiently flushed while in operation. Don't believe the water saver stuff some claim with dual membranes, its not that easy.

 

[ash9965]

just was getting a little frustrated yesterday as the yard flooded before 1 bucket filled . I have to come up with a way of diverted waste water I guess also took about an hour just for 1 5 gallon bucket ... Does that seem reasonable ?

 

[ash9965]

also so what's the real point of using RO water what is the main thing we are trying to keep out of our tanks and what are the main benefits we are achieving

 

[ash9965]

Here is the replacement set I bought

http://www.bulkreefsupply.com/brs-4-stage-ro-only-replacement-filter-kit.html

 

[AZDesertRat]

Depending on your water pressure and water temperature that could be normal.
Two things, you have a dual membrane system you say so right off you need a minimum of 65 psi to operate it, a single membrane system can operate efficiently at 50 psi.
With two 75 GPD membranes and 65 psi you should be able to make 135-150 GPD or around 6 gallons an hour at 77 degrees F.

Don't try to warm the water though since cold water actually treats better than warm water and will make your DI last longer. Use a measuring cup and measuer the waste flow for exactly one minute then do the same with the treated flow. It should be about 4 times as much waste as treated if it is working correctly.

What is your pressure, temperature, waste ratio, tap TDS, RO only TDS and final RO/DI TDS? Are you using softened water or hard water?

I would not have bought that filter set personally. Did you know you can actually see 40 microns with the unaided human eye? 5 microns is very coarse in my book, I never use anything larger than 1 micron and usually use a 0.5 or 0.2 micron sediment filter and one single 0.5 micron 20,000 gallon carbon block since it is being protected from junk by a good low micron sedimen tfilter. They use two carbons because the sediment filter is coarse and teh first carbon is sacrificial to catch what the sediment filter should have. You could use the second carbon caniste ras a dual DI and get much more bang for your buck that way.

 

[ash9965]

what filter set do you recommend also if my pressure is too low how can I increase it

 

[ash9965]

also it is the triton 200 GPD system

 

[AZDesertRat]

That scares me. Most older 100 gpd membranes were on 90% rejection rate when new compared to 96-98% for a 75 gpd membrane. Remember every 2% drop cuts the DI life in half. You need to test your TDS before spending any more money on that system to see what you have. Unfortunately, rarely are used RO systems a bargain unless you know the complete history going in.

The first nly way to raise pressure is a booster pump such as the Aquatec 8800.

For replacement filters I suggest the 0.5 micron set from Spectrapure with the SilicaBuster or SuperSilicaBuster DI cartridge.

 

[ash9965]

when I get off today I will look at the TDS and let you know

 

[ash9965]

TDS is 114 from faucet and 0 coming out of RO unit pressure is at 60 going in and I was able to get about 10 - 12 gallons yesterday out of about approximately 32 plus or minus gallons of waste ,( took a couple of hours ) so everything seems to be on the right track correct ?

 

[AZDesertRat]

You need 3 TDS readings. Tap, RO only before the DI and final RO/DI.
Since the RO membrane does 90-98% of the treatment the RO only TDS is the most important number but everyone overlooks it.
60 going into a dual membrane system is not going to be very efficient, 65 is the recommended minimum.

 

[ash9965]

Thanks