RO/DI Help

[gtrider]

Hi,

I have a 4 stage 100 GPD RO/DI (marine depot brand).

When i set it up, i did the initial flush with the DI filter installed.

My systems seems pretty slow. It filled a 55g drum of waste water before i even got 4 gallons of fresh water. Does that seem normal or could it possibly be due to not removing the DI filter before the initial flush?

Tim

 

[WWIII]

I doubt it has to do with not removing the di for initial flush. Like 99.99% sure. Do you know what your water pressure is? You should be closer to 4 to 1 waste to clean water. Sounds like you're more than double that (or half that) depending on how u look at it. Something is either hooked up incorrectly or the water pressure is too low, would be my guess.

 

[gtrider]

The pressure is at 40 psi. i have it hooked to a standard sink in my basement. I didn't realize that would make a difference.. figured it would just make the water slower. Any idea on how to ramp up the water pressure on a specific sink?

 

[chipmunkofdoom2]

The DI filter is not the problem. Your pressure is not the problem either, unless you're running two membranes. More pressure is usually better (within reason), but almost all TFC membranes will work at 40 PSI. Something else is going on.

First thing is to check is the flow restrictor. Make sure it's installed, and make sure it's sized properly for your system. Second, if you have the type of flow restrictor that comes with the valve, make sure the valve isn't open.

Keep in mind that if your RO/DI system is adjusted properly, it should be sending about 4 gallons out of the waste water line for every gallon of product water you get. If you must save the waste water, make sure your reservoir is large enough, or has an overflow that will allow excess to go down the drain.

 

[gtrider]

@chipmunkofdoom2 thank you. Below is a diagram of my system. Where is the flow restrictor?

 

[WWIII]

The flow restrictor will probably be in the waste water elbow or line. 40 psi isn't great, but shouldn't be a problem. Did you change out the stock ro membrane or anything since you purchased the unit?

 

[chipmunkofdoom2]

The flow restrictor should be on the "Waste Water To Drain" line. It might look like one of these, or it could have two Y adapters with some tubing and a valve in between.

 

[Bruno516]

Can you provide 3 more things for us?

What is the flow rate in ML/MIN? Grab a measuring cup and put the waste line in it for 30 seconds - times by 2 and you will get ML/MIN. Do this for waste and product;
--Waste ML/MIN?
--Product ML/MIN?

What is the water temperature?

 

[WWIII]

Looks like marine depot uses the inside style like spectrapure does. It should look like this and may be worth changing out or contacting marine depot about...

 

[JoshH]

Edit, didn't realize some systems had internal ones lol never seen or heard of that.

 

[gtrider]

I dont see a restrictor. the pics above are of the water water line. there i a valve which i never touched.

 

[WWIII]

With your setup you should expect to get a little over 10 gallons of fresh water for every 50 gallons of waste. This should take a little over 2 hours to produce.

 

[WWIII]

I dont see a restrictor. the pics above are of the water water line. there i a valve which i never touched.

The restrictor should be inside the yellow line, probably in the small section where the flush valve is opposite of.

 

[gtrider]

I get 4g of fresh and it takes 1hr 45min

 

[chipmunkofdoom2]

Is the yellow line going out the window the waste water? If so, I think that's the problem. It looks like your system has a capilary style restrictor. That valve in the pictures needs to be closed. It looks like it's open right now. That valve should only be opened to bypass the restrictor so you can flush the membrane.

 

[gtrider]

yes, the yellow is the waste water line. Okay so i noticed that valve on the blue line... that needs to be closed?

 

[chipmunkofdoom2]

yes, the yellow is the waste water line. Okay so i noticed that valve on the blue line... that needs to be closed?

Yep. You only open that to flush your membrane, which really doesn't need to happen that often.

 

[WWIII]

If there's no restrictor, or the flush valve is open, the water will go the least path of resistance, which would be out the open waste line (no restrictor) OR the open flush valve yto waste line. The restrictor forces the water more through the ro membrane, through the di, and into your fresh rodi water container.

Yes the valve needs to be in the closed position when you are making water and only opened when you wish to flush the membrane.

Good catch @chipmunkofdoom2 ! Sometimes it's the simple things. :-)

 

[gtrider]

@chipmunkofdoom2 and @WWIII you guys rule! Wow i feel dumb. I just made a batch but should make some more for my ATO tomorrow and i'll report back. Thank you guys so much!

 

[WWIII]

@chipmunkofdoom2 and @WWIII you guys rule! Wow i feel dumb. I just made a batch but should make some more for my ATO tomorrow and i'll report back. Thank you guys so much!

Trust me, we've all been there. When I first setup a rodi system I just saw a bunch of lines and filters going every which way. After a while it just clicks how it all works and why.

I was running through di resin rather quickly and in finding a solution I came to know more about an rodi system than I ever would have imagined.