Kent RO/DI HI-S 60 GPD Taking Forever

Trekkie

Premium Member
Now I don't expect to get 60 GPD out of my water filter but recently (last week) it's gone from filling a 5 gallon bucket in a couple of hours to taking almost 24 hours.

Looking at the waste line it appears to be coming out slow as the blue line is coming out in drops every few seconds.

Looking at the open filters I'm not seeing any color change in the resin or any obvious blockages, my understanding is the filter itself should last 3 - 5 years and I'm coming up on about 2.

I only do 15 gallons or so a month, maybe 20 at the most with top-offs.

Any ideas why it got so slow all of the sudden?
 

AZDesertRat

In Memoriam
Two things affect RO/DI output, temperature and pressure. That unit is designed to produce 60 GPD at 65 psi and 77 degrees F water temp. If either or both are less than that then it can cut production significantly. I would suggest getting an inline pressure gauge and install it between the carbon filter and the RO membrane to measure the pressure that is actually hitting the membrane and a thermometer to measure your tap water temperature.
To give you an idea of the effects I have a 90 GPD Spectrapure MaxCap system that is rated at 90 GPD at 60 psi and 77 degrees F. In the summer my water temp can reach as high as 83 and my pressure at the membrane is a steady 64 psi and I get almost exactly 100 GPD on the nose. Right now I still have the very same 64 psi but my water temperature is 60 to 64 degrees and I get 62 GPD. Thats quite a difference for temperature only!
Here is a link to Dow Filmtecs graphs that show the effects of both on output. Your membrane would be the same as the Dow 50 GPD which is at 50 psi.
http://www.dow.com/PublishedLiterat...seps/pdfs/noreg/609-09010.pdf&fromPage=GetDoc
 

Trekkie

Premium Member
I forgot about temp, been a while since it got cold. I've always had bad pressure that's why I said never expected high pressure. My Kent Maxxima Hi-S has a pressure gauge near the filter, and it's at a whoppin 5 psi which is low. Think it's time to get a new round of sediment/carbon filters.
 

Reefmaniac1

New member
<a href=showthread.php?s=&postid=9290368#post9290368 target=_blank>Originally posted</a> by Trekkie
I forgot about temp, been a while since it got cold. I've always had bad pressure that's why I said never expected high pressure. My Kent Maxxima Hi-S has a pressure gauge near the filter, and it's at a whoppin 5 psi which is low. Think it's time to get a new round of sediment/carbon filters.

Sounds like a good place to start!:cool:
 

AZDesertRat

In Memoriam
Always replace the filters every 6 months if not more often. Disinfect the housings while you have it apart for filter replacement.
 

BONDQ

Premium Member
<a href=showthread.php?s=&postid=9291355#post9291355 target=_blank>Originally posted</a> by AZDesertRat
Always replace the filters every 6 months if not more often. Disinfect the housings while you have it apart for filter replacement.

Just curious, what would we be disinfecting for and what chemical would be reef-safe to do this with?

If he's on a city water supply, wouldn't there be trapped chlorine in the filters to inhibit bacterial growth?

Just curious.
 

Trekkie

Premium Member
Good question, didn't see that response and replaced my filters last night. 2 year old sediment filter was a nice shade of brown, and I drink that every day wonder what it's filterin out.
 

Reefmaniac1

New member
<a href=showthread.php?s=&postid=9349586#post9349586 target=_blank>Originally posted</a> by BONDQ
Just curious, what would we be disinfecting for and what chemical would be reef-safe to do this with?

If he's on a city water supply, wouldn't there be trapped chlorine in the filters to inhibit bacterial growth?

Just curious.

The chlorine in city water doesn't kill everything. You can get algae growing in a bucket of tap water...

A city health official will tell you that the amount of chlorine in tap water comes nowhere NEAR their minimum standards for using in a pool. Keep that in mind the next time you drink a glass...;)
 

Trekkie

Premium Member
So what do you recommend for disinfecting that won't damage any of the filters? Specifically thinking about the DI cartridge part.
 

BONDQ

Premium Member
<a href=showthread.php?s=&postid=9349931#post9349931 target=_blank>Originally posted</a> by Reefmaniac1
The chlorine in city water doesn't kill everything. You can get algae growing in a bucket of tap water...

A city health official will tell you that the amount of chlorine in tap water comes nowhere NEAR their minimum standards for using in a pool. Keep that in mind the next time you drink a glass...;)

I agree, I don't drink water from the tap and I understand what you're saying here.

What I don't understand is how this applies to fish. Is that algae you speak of dangerous to fish?

Other than the chemicals, metals, and lack of salt in tap water, wouldn't the water otherwise be safe from the premise of bacteria or viruses?

In other words, isn't the main reason for using a RO/DI (which BTW many, many people still don't use) to remove chemicals and metals?

Is there something I'm missing here?
 

AZDesertRat

In Memoriam
You disinfect with normal unscented bleach. While the prefilter and carbon block housings are empty, add 2 or 3 tablespoons to the prefilter housing and screw the empty housings back on. Disconnect the 1/4" line from the last carbon where it plugs into the RO membrane housing and stick this into a bucket or sink, this is very important so you do not get chlorine to the membrane, and open the water supply. Flush a few gallons through and when any odor of chlorine is past, reinstall the filters and hook back up to the membrane and you are set for another 6 months to a year. If you are replacing the membrane leave the line connected and flush the bleach through the membrane housing too.
Bleach goes a long way so don't over do it, its not a case of if a little bit works good a lot works better, you will have a hard time getting it all out.
The reason for doing this is bacteria and viruses can and do grow in the housings, remember your carbon has adsorbed any residual disinfectant the utility put in so when your housings are setting there in the summer time with temps going up and possibly direct sunlight shining through the clear housings you have the perfect breeding ground for any nasties that find their way into a water system.
 

raddogz

Premium Member
<a href=showthread.php?s=&postid=9349985#post9349985 target=_blank>Originally posted</a> by Trekkie
So what do you recommend for disinfecting that won't damage any of the filters? Specifically thinking about the DI cartridge part.

I believe a bleach solution would work on the housings.
 
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