RODI question

[m0nk3y69d]

Hey everyone I have a 6 stage 75gpd rodi from BRS and it seems like it takes forever to make water and when I say forever I'm talking 5hrs to make 10g of water dose anyone have any advice for me on how I can get more water production out of my rodi

 

[AZDesertRat]

What is your incoming water pressure, water temperature, tap TDS and your exact measured waste ratio? You don't happen to have a flush kit on it and have the valve in the flush position do you?

 

[smalltimereefer]

I have the same RODI it' supposed to make about three gallons hr, try the valve on top by the filter that is laying on top. That is a bypass, watch the flow coming out of your black line as you put it in one position or another. It should be in the position that let's the least amount of water flow through the black tube.

 

[smalltimereefer]

Sorry I just read desert rats post, this is the valve I'm speaking of. You should have it.

 

[m0nk3y69d]

Yes I have a flush valve on the system and no its not open and I'm not sure of the incoming water pressure but the pressure gage on the system bounces between 40 and 60 psi and the waste ratio I'm not sure of either and the temp is cold I have a saddle valve that is on my cold water line that feeds my washer

 

[AZDesertRat]

You need to know the temperature and waste ratio. If your pressure is 40-60 then you have problems elsewhere. 75 gpd membranes are rated at 75 gpd at 50 psi, 77 degrees and 250 TDS and a 3:1 to 4:1 waste ratio. Measuring the waste ratio is simple using a measuring cup and click or watch for exactly one minute from the waste line then from the treated line. Temperature can be measured with any thermometer and a cup or glass of tap water. If you own a RO or RO/DI it is very important you keep track of all of the things I asked about as each one has an effect on how well a system works.

 

[AZDesertRat]

And trash the saddle valve and get yourself a brass garden hose wye with individual ball valves from any Lowes, HD or even Walmart for about $8. Needle valves are often a source of problems.

 

[m0nk3y69d]

My home TDs is always between 600 and 800 and I will have to get the tempature and waste ratio for you

 

[m0nk3y69d]

I'm not lucky enough to live in an area with town water and we have very hard water

 

[AZDesertRat]

When you say it bounces between 40 and 60 is that literally the case or is it just between those two depending on time of day and water demands? Are you on a domestic well with a pressure switch operating between those two?
My Phoenix tap water varies between 550 and 850 so that is not unusual.

 

[m0nk3y69d]

I'm watching my pressure gage now and it started at 55 and is down to 40 and its Ben 10 min and my waste ration seems OK at 1 min I got 2 cups of waste and 1/2 cup of rodi

 

[m0nk3y69d]

Its now down to 35
psi

 

[AZDesertRat]

If you are on a domestic well system, watch your well or booster/pressure/bladder tank pressure gauge and the RO pressure gauge to see if the readings are similar. It is usually recommended you have a RO booster pump when on a domestic well to raise the RO pressure since raising well pressure is much more expensive when you look at the power and extra wear on the pump.
A RO booster also makes up for cold water.

 

[m0nk3y69d]

OK it got down to 30 and is now back up to just under 60

 

[AZDesertRat]

35 is too low for a RO membrane go operate. The absolute bare minimum is 40 and only then if you have warmer water to make up for it. But cold water and higher pressure is much much better than warm water and low pressure.

 

[m0nk3y69d]

So I'm thinking I'm going to need a booster pump

 

[AZDesertRat]

Just for giggles using the calculator found at Buckeye Hydro RO/DI supply, lets assume your water temperature is 50 degrees F; At 30 psi you will only make 23 gallons a day if you only had 250 TDS, less at your TDS. At 35 psi and 50 degrees it only rises to 28 gpd so still around 1 gallon per hour best case. I think you need an Aquatec 8800 booster pump.

 

[AZDesertRat]

Take the same 50 degree water but boost it to 80 psi and it is now exactly 75 gpd at 250 TDS. Big big difference and best of all your DI will last 4 or 5 times longer.

 

[m0nk3y69d]

Where is the bes place to get one and how much dose it usually cost and how do they work I have never looked into one and know nothing about them lol

 

[AZDesertRat]

Spectrapure, Buckeye Hydro, amazon, maybe BRS and many other places. Is you are filling an ATO or making water automated you will want one with a pressure switch, either way you need the heavy duty 24v power supply. Watch out for eBay sellers that list a low price and don't include the power supply or pressure switch. Expect to pay around $139-$150 for everything. Get only an Aquatec 8800 or the comparable ShurFlo, the imports and clones don't last nearly as long.