Kent RO unit question

[Mark Cooper]

I've gotten a Kent Hi-S RO unit from a buddy who has gotten out of keeping
fish. He said this is a 35 gpd unit, but I'm not so sure of that. It only
takes it about 4 hrs to fill a 13 gallon container, so I wonder if it's not
actually a 60 or 75 gpd unit.

How long does the membrane in this unit last? Marinedepot website says 3 to
5 yrs, but they want to sell more, so wondering if that's a low estimate of
the useful life for the membrane?

Thanks,
Mark

[Pszemol]

"Mark Cooper" > wrote in message .. .
> I've gotten a Kent Hi-S RO unit from a buddy who has gotten out of keeping
> fish. He said this is a 35 gpd unit, but I'm not so sure of that. It only
> takes it about 4 hrs to fill a 13 gallon container, so I wonder if it's not
> actually a 60 or 75 gpd unit.

Are you sure you did not mix product and waste water outlets ?
The slow-flowing is the product, clean water. Fast flowing is the waste (brine).
KENT full size RO units are "Available in 35, 60 and 120 GPD Units, in clear canisters"
http://www.kentmarine.com/waterfilters/fullhis.html
It is highly unlikely you will get nominal output of 60gpd from a 60gpd unit
because the input tap water is usually colder than optimal temperature
and lower pressure than optimal for membrane. You should expect normally
about 70-80% (or less!) of the nominal output in real-life scenarios.
So my bet would be - based of amount of water you created - you get the
brine/product outputs mixed or... this is 100gpd unit.

There could be other thing, also - one of the seals could be leaking.
The best way to test if filter is working is to test conductance of the
water coming out of RO filter (before DI stage, if such stage present).
The TDS meter should read a value close to zero ppm (usually less than 10ppm
depending of your incoming tap water hardness). Also, I would recommend
replacing prefilters, especially the carbon filter - if it is old and
lets chlorine go to the membrane it will damage the membrane.

> How long does the membrane in this unit last? Marinedepot website says 3 to
> 5 yrs, but they want to sell more, so wondering if that's a low estimate of
> the useful life for the membrane?

This estimate is about right and you could shorten the membrane life
mishandling it (like keeping it dry etc).

[Mark Cooper]

"Pszemol" > wrote in
:

> "Mark Cooper" > wrote in message
> .. .
>> I've gotten a Kent Hi-S RO unit from a buddy who has gotten out of
>> keeping fish. He said this is a 35 gpd unit, but I'm not so sure of
>> that. It only takes it about 4 hrs to fill a 13 gallon container, so
>> I wonder if it's not actually a 60 or 75 gpd unit.
>
> Are you sure you did not mix product and waste water outlets ?
> The slow-flowing is the product, clean water. Fast flowing is the
> waste (brine). KENT full size RO units are "Available in 35, 60 and
> 120 GPD Units, in clear canisters"
> http://www.kentmarine.com/waterfilters/fullhis.html It is highly
> unlikely you will get nominal output of 60gpd from a 60gpd unit
> because the input tap water is usually colder than optimal temperature
> and lower pressure than optimal for membrane. You should expect
> normally about 70-80% (or less!) of the nominal output in real-life
> scenarios. So my bet would be - based of amount of water you created -
> you get the brine/product outputs mixed or... this is 100gpd unit.
>
> There could be other thing, also - one of the seals could be leaking.
> The best way to test if filter is working is to test conductance of
> the water coming out of RO filter (before DI stage, if such stage
> present). The TDS meter should read a value close to zero ppm (usually
> less than 10ppm depending of your incoming tap water hardness). Also,
> I would recommend replacing prefilters, especially the carbon filter -
> if it is old and lets chlorine go to the membrane it will damage the
> membrane.
>
>> How long does the membrane in this unit last? Marinedepot website
>> says 3 to 5 yrs, but they want to sell more, so wondering if that's a
>> low estimate of the useful life for the membrane?
>
> This estimate is about right and you could shorten the membrane life
> mishandling it (like keeping it dry etc).
>

I checked the lines and they are connected right, lots of waste water
compared to a drip drip drip of product. I think my buddy just remembered
wrong as to what unit he has. I estimate it's putting out about 40 gpd,
which seems realistic for a 60 gpd??

He said he replaced the cartidges a few months ago, so I think I probably
have a few months of use out of them. It was never allowed to go dry, so
I think the membrane and cartridges should be fine.

Regarding the membrane, he had the unit hooked up to a float valve, so
when the storage tank got full it would shut off flow. Would this extend
the operational life of the membrane, since it wasn't processing all the
time?


Thanks,
Mark

[Pszemol]

"Mark Cooper" > wrote in message .. .
> I estimate it's putting out about 40 gpd,
> which seems realistic for a 60 gpd??

4 hours to fill 13 gallons gives you 78 gallons per 24 hours.
Unrealistic for 60gpd :-) More likely it is a 100gpd membrane.

> Regarding the membrane, he had the unit hooked up to a float valve, so
> when the storage tank got full it would shut off flow. Would this extend
> the operational life of the membrane, since it wasn't processing all the
> time?

Do not know. To check membrane the only test is TDS meter.