Adding a second membrane to RODI unit

[hiimsean]

I'm about to order the http://www.bulkreefsupply.com/brs-150-gpd-water-saver-upgrade-kit.html">upgrade kit</a> for my 75gpd unit (BRS 5 Stage Plus). I've watched the video a few times and my main question is do I need to change my flow restrictor to a 150gpd as opposed to the 75gpd restrictor? The kit doesn't include it and the video doesn't show them changing it out either.

I was just resading an old thread about people adding the upgrade kit, [IMG]http://www.atlantareefclub.org/forums/showthread.php?t=74476&highlight=dual+membrane">http://www.atlantareefclub.org/forums/showthread.php?t=74476&highlight=dual+membrane</a>, and in post 15 Russ from Buckeye Field Supply talks about using different flow restrictors to reduce the waste ratio.

I am also purchasing a booster pump with this upgrade. My goal is to be able to produce water faster and reduce my waste ratio, which I believe to be right around 4:1 waste:RODI.

 

[acroholic]

IIRC, Russ is talking about using a different flow restrictor instead of adding a second membrane, not in addition to adding a second membrane. He usually discourages folks from adding a second membrane. If you add a second membrane, they both have to be the same type (GPD), and you use a similarly rated flow restrictor, but you do not have a flow restrictor on the waste line of the first membrane, you place it on the output of the second membrane.

We can get away with this here because we have very low TDS in our tap to start with. BRS does not recommend the 150 gpd upgrade kit for high TDS areas.

 

[hiimsean]

So since they will both be 75gpd membranes, a 75gpd restrictor is what I should keep on there?

 

[acroholic]

Yes, but the restrictor should be on the waste output of the second membrane. No restrictor on the waste output of the first.

 

[hiimsean]

So exactly like the instal video shows.

 

[twhaddon]

I have the 75gpd RODI from BRS and my water pressure was only around 40psi. It would take almost 20 minutes to get 1 gallon of rodi. I then purchased the 150gpd upgrade and the booster pump as well. I consider this one of my better decisions. I can now get about 3 gallons in under 15 minutes and my pressure is around 90psi.

I hope you find the same success. Good luck!

 

[hiimsean]

My water pressure is about 40psi as well. I'm excited to get it and put it to use. I ordered the setup this morning, got in on a Group Buy plus $10 off of my order

 

[acroholic]

You'll see a big increase in production going from 40 psi to 75-80 psi. I run my booster at 75 psi, but when I first bought my booster, I called BRS and they said up to 80 is great. Your pump is adjustable pressure, if you didn't already know.

 

[giulianom]

Acroholic;924986 wrote: You'll see a big increase in production going from 40 psi to 75-80 psi. I run my booster at 75 psi, but when I first bought my booster, I called BRS and they said up to 80 is great. Your pump is adjustable pressure, if you didn't already know.

So if my Aquatec 8800 booster pump is delivering 60PSI at the membrane, should it be adjusted to deliver 75-80PSI?

 

[acroholic]

GiulianoM;925024 wrote: So if my Aquatec 8800 booster pump is delivering 60PSI at the membrane, should it be adjusted to deliver 75-80PSI?

It can be, but doesn't have to be. I talked to the guy that appears in all the BRS Videos, and he told me 80psi is good. If you want to be careful, call them to confirm, would be my best advice. But I've been running at 75-80psi for a couple years. Same pump, Aquatec 8800.