View Full Version : RO unit and tap water pressure question-
Hello-
I just purchased a coralife 4 stage RODI unit, which I have connected to an indoor faucet.
How do I know if my water pressure is sufficient? When I turn on the cold water, the water really blasts out- so should this be good enough?
I have read several posts about filter use, however I can't seem to find my answer. Thanks for your help!
Jano
Reefscape
06-02-2008, 1:46 PM
Sounds like it should be fine. The only real way to know is to actually get the water pressure tested at the faucet....
The Zigman
06-02-2008, 3:17 PM
you usually wast at least 65PSI at the membrane...
but no more that 100psi in most cases.
My RO has a pump that forces the water through the membrane at about 80PSI.
Sounds like you should be ok though. How long does it take to produce a gallon of clean water?
You could install an inline pressure gauge like the one pictured on this page:
http://www.drsfostersmith.com/product/prod_display.cfm?c=3578+4395+4533&pcatid=4533
When placed between the last pre-filter cartridge and the RO membrane, it's useful for monitoring if / how fast your pre-filter cartridges are clogging.
The majority of homes on municipal water systems have adequate water pressure, at least on the ground floor. Most of the people that require a booster pump have a well. If the cold water is coming out that hard, you probably have plenty of water pressure.
jcono
06-02-2008, 10:31 PM
thanks for the replies- so far it takes about 2 hours to make a gallon- I may try a different faucet to see if I have better pressure.
What is the unit's output rating (gallons per day)?
Two hours to make one gallon is pretty slow, unless it's only rated for ~25 gpd.
jcono
06-04-2008, 10:13 AM
It's a 50 gpd unit- I bought it used- guess I prob. need to replace the prefilters..
ncompany
06-04-2008, 2:44 PM
Colder water slows the process down as well should be around 70 degrees or so as well as good pressure
If I open up both hot and cold faucets, I get better pressure and water around 70 degrees. Then why do my instructions say to use cold water only? I'm guessing because hot water really shouldn't be used.
kcress
06-04-2008, 4:23 PM
By cold they mean NOT HOT. So 80F is fine. 80F would make a substantial difference over 50F water.
The warmer the water the more likely you could get bacteria going in your filter system somewhere.
There's three things that will have the most impact on RO production -- water temp, water pressure, and incoming TDS (Total Dissolved Solids). Low water temp, low water pressure, and high incoming TDS will result in very slow RO production rates.
Hot water is not good to use since it can damage the RO membrane. Warm water is ok, as long as you can effectively control the water temp enough to make sure it doesn't get too hot.
Depending on how long it's been since the former owner changed the prefilters, it might be a good idea to change them out.
BuckeyeFldSup
07-29-2008, 6:17 AM
If you are not clear on the history of the unit, I'd start with sanitizing the system, and a new round of filters.
What was said above re temperature and pressure is true. Membranes are factory speced at 77 degrees F, and 50 or 60 psi depending upon the brand of membrane. So without a pressure gaige, you are flying blind... That said, 2 gals per hour from a 50 gpd system is about right (2 gals per hr x 24 hrs = 48 gpd).
Russ