hey az , ro question

[81Shaun]

hey ,it me again. I was going to ask you why does my ro pressure gauge drop from 80 psi to about 75-76 psi ? also s fluctuate over 80 psi like 85- 90 roughly. now im using cold water pretty cold and where it hooks to my faucet its dripping so im assuming that might be causing it ? or trapped air or cold water ? now im aware that pressure drop is related to filter wearing out but that wouldn't apply to me as the unit is new. tds is 400 going to the unit but just was curious on this . thanks

 

[AZDesertRat]

When you first hook it up or start it you are probably reading static or non flowing pressure. You can confirm this by either temporarily kinking or installling a ball valve on both the treated water line and the waste line then turn it on. This is your reference or starting point for pressure at the tap. It may change depening on usage in your neighborhood, time of year etc.

When you are making water the pressure will drop some as you are now bleeding some off via the waste line to keep the RO membrane flushed and sending another portion through the RO membrane (4:1 waste ratio etc.). It should not drop significantly which could be an indication of too much going to waste or as the system gets used, dirty, fouled or plugged sediment and carbon block filters. Note the pressure when you are making water and write that down as a reference point for new clean filters and refer back to it every so often to see if it drops as the filters get dirty.

I find it easier to use two pressure gauges so I can see at a glance what my pressure and filter conditions are, one before the sediment filter and the one that is on the membrane housing which is after the carbon block. When I start to see more than a 2-3 psi drop between the two I know my filters are in need of replacement. This is if I stretch the filter replacements past the recommended 6 months or have unusually dirty water.

 

[81Shaun]

Okay, I have a 3 way ball valve coming out of the membrane im using for TDS creep and for Drinking water so what I did was shut the treated water fof and kinked the waste line and turned unit on. I got pressure that normally is 80 psi to about 90 psi somewhere in that area. the gauge still moved and a few times shot up to around 100 psi. also pressure did drop to below 80 id say 75-76 somewhere in that area. so must be static pressure right ? what exactly is static pressure ? also the gauge ill pick one up is it the gauge with 1/4 fittings right ? and what would be a good placement for installing one ? closer to the sink plug or closer to the sediment or really don't matter ? l also hooked up my other rodi to check and the water went floating from 80 psi down to about 76 or 77 somewhere around thre but i didn't kink it.

 

[AZDesertRat]

Pressure is usually very steady in most areas this time of year. You must either be on a master metered system such as an apartment with other users, close to a well or booster station that cycles on and off or near the end of a dead end line? My pressure is almost rock steady at 68 psi year round.

The static pressure is the non-flowing or steady/constant state pressure in the water distribution system. Most areas try to provide a minimum of 40 psi and most that have fire protection (hydrants) on the same domestic system have 60-80 psi so they can still provide a minimum of 20 psi with hydrants flowing to fight a fire. Pressures can change throughout the day with demands like the early morning showers and breakfast dishes, lunch time, evening showers, the 7th inning or halftime flush etc. They can also change seasonally like lower during summer with lawn watering or on weekends when everyone is home washing the car, doing laundy etc. But normally the changes are more gradual both down and then back up unless you are close to the source/booster station or at the end of the line.

 

[ReefMadScientist]

Hey AZ,

I learned that if you add some line to the RO waste water, you can actually increase or decrease psi but cutting slits, etc. For example, I have my RODI system running in my garage and tapped into the main faucet outside. The waste water go to my yard and drips to my plants.

 

[81Shaun]

no I live in a house which is a dead end road but im like not towards the end of the road closest house to me is about 200 yards away on either side. only thing i can think would cause it then would be where im hooking on to my faucet its leaking around where its screwing on to my freshwater python cleaner hook up the rodi end screws on to there maybe that could be why doing that and could see why would but i tighten as tight as i can and it still leaks so im not sure?

 

[AZDesertRat]

You might try a pressure gauge on an outside hose bib. A gauge kit is like $8 at Lowes and HD and usually has a 0-100 psi or 0-160 psi gauge and a hose thread adapter. I can't imagine the faucet is leaking enough to change pressure that much if the cold water is turned on all the way as it should be.'
You might also check to see if you have a pressure regulator on your incoming water supply line. The diaphragm in it may be failing or need adjustment.
My wife is in Ashland Ohio right now for a week visiting family, sent me pics of the white stuff! Our only white stuff is alkaline soils and sand?

Nacho, be very very careful when extending the waste line and especially when using the waste for landscape. When you do that you are violating all plumbing and health codes since it is considered a direct cross connection of backflow risk. There is always the possibility something could happen to draw water back into the system and that isn't good. The better idea is to run the waste into a poly barrel or one of those blue barrels with an air gap which is UPC and code approved then run water out of the barrel by gravity to the landscape.
The other issue is lengthening the waste line lessens the waste ratio meaning your membrane is not being sufficiently flushed and will fail sooner, costing you more money. IF you do decide to lengthen the waste line make very sure to measure your waste ratio with the new configuration and adjust your waste ratio back to 4:1. here in Phoenix and the Southwest it is important to keep it at that with our very hard water and high TDS. If you have softened wate rbe sure to use that for the RO/DI, membranes love softened water and will last many times longer since it acts as pretreatment.

 

[ReefMadScientist]

You might try a pressure gauge on an outside hose bib. A gauge kit is like $8 at Lowes and HD and usually has a 0-100 psi or 0-160 psi gauge and a hose thread adapter. I can't imagine the faucet is leaking enough to change pressure that much if the cold water is turned on all the way as it should be.'
You might also check to see if you have a pressure regulator on your incoming water supply line. The diaphragm in it may be failing or need adjustment.
My wife is in Ashland Ohio right now for a week visiting family, sent me pics of the white stuff! Our only white stuff is alkaline soils and sand?

Nacho, be very very careful when extending the waste line and especially when using the waste for landscape. When you do that you are violating all plumbing and health codes since it is considered a direct cross connection of backflow risk. There is always the possibility something could happen to draw water back into the system and that isn't good. The better idea is to run the waste into a poly barrel or one of those blue barrels with an air gap which is UPC and code approved then run water out of the barrel by gravity to the landscape.
The other issue is lengthening the waste line lessens the waste ratio meaning your membrane is not being sufficiently flushed and will fail sooner, costing you more money. IF you do decide to lengthen the waste line make very sure to measure your waste ratio with the new configuration and adjust your waste ratio back to 4:1. here in Phoenix and the Southwest it is important to keep it at that with our very hard water and high TDS. If you have softened wate rbe sure to use that for the RO/DI, membranes love softened water and will last many times longer since it acts as pretreatment.

Good thoughts.

I have the waste water running outside the wall down to the shrubs/trees. Definitely no way the water can run back into the system as I installed a few ball valves to close down the system when I am not running. I do have two auto-shutoff valves but I like to manually shut the ball valves just in case.

Also, my BRS 6 stage Deluxe has a membrane flush lever that I use every now and then. I went to Spectrapure here in Tempe and they upgraded my membrane and flow valves to 90psi. Awesome guys there and they will test your kits.

 

[AZDesertRat]

Ball valves are not backflow preventers. What if you are wasting to the shrubs and Joe Contractor digs up the water main down the street and causes a backflow. The City comes out and shuts the main down and your water sucks back into the system to fill the vacuum it created, sucking your fertilizer and crap back into your RO and your home. An air gap prevents this since it will only suck air back and not waste. This is why UPC rated RO drinking water systems have air gap faucets so your waste line leads out of the membrane, up to the bottom of the faucet where there is an air hole then back down to your P trap or drain. When pressure is lost it sucks air and not saste from the sink P trap.

Also how did you address the longer waste line and adjust your final waste ratio? So called "flush kits" have absolutely nothing to do with this and have no proven documented value. Membranes must be continually flushed when in use, especially in Arizonas extremely hard and high TDS water. Measure your waste and trim the restrictor to get it back to 4:1 if it changed.

Spectrapure is an awesome vendor for sure, I have used their products for over 10 years now and haven't had anything bad since. My DI went from 150 gallons per cartridge to 830 gallons on my first DI from them and its been even better ever since.

 

[81Shaun]

okay, went down and checked out the only thing i no is there is a small ajust that is running into my furnace its located on the hot water tank. im not sure what that is about ? only other thing is a sharkbite main water shut off. and its wide open. im just assuming it something going on with the city water as it was staying a solid 80 psi these unit ive only made about 20 gallon with both systems . anyhow if i buy another gauge and install between the water and sediment where should it be installed ? spectra pure has one 15.99 1/4 push fittings so ill probably just buy one from there. ya its crazy that much stuff is allowed in the water I honestly didn't think this water is that bad until now. ya ashland ohio ive been there im thinking before. im south of there close to the ohio river south eastern ohio athens county.

 

[AZDesertRat]

Install the gauge between your water supply, faucet adapter, feed water valve or whatever and the sediment filter. Thiswill give you a baseline to tell when your sediment and carbon block filters are becoming fouled or plugged when you compare the two gauges side by side. More than a couple psi drop is time for a filter replacement. If you still have wandering pressures you need to look further but it may be beyond your control. As long as you have 40+ psi it is not a huge deal but more pressure is always better with RO.

 

[81Shaun]

Thanks Az, appreciate the help I just checked it again the other day I completely closed off the output product line and the waste water line and the gauge shot up to like 90 ish psi but the pressure did drop and kept moving around .so that would eliminate the system wouldnt it ?

also was going to ask how do I go about sterilising one of these machines? I no bleach will kill the membrane but what should I do with the membrane while flushing bleach water through? or can I skip running water into the membrane housing altogether? I am using this system for drinking water so just want to make sure it gets cleaned. I am sorry if there are a ton of threads on this but not sure on how to sterilise one of these. I am a lil bit leary running bleach into the thing though kind makes my stomach a lil uneasy. anyhow... thanks man

 

[81Shaun]

think someone said peroxide will work also ?