Two 150gpd ro membranes
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Brew12
Electrical Gru
Make sure you get the right size flow restrictor if you give this a try.
chipmunkofdoom2
Always Making Something
What would be the purpose of running two 150 GPD membranes? Why do you need 300 GPD total production capacity?
Brew12
Electrical Gru
I have no idea what the correct size is.... I just know some people have caused themselves issues by upgrading their membrane without making the necessary changes to the flow restrictor.
redfishbluefish
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If I'm not mistaken, I believe you don't get the excellent rejection of 98% plus once you go up past 90 gpd. Check the rejection of the 150 membranes.
EDIT TO ADD: Just looked up BRS's 150 gpd, and I guess I'm eating my words....their membrane has 98% rejection at 65 pounds.
EDIT TO ADD: Just looked up BRS's 150 gpd, and I guess I'm eating my words....their membrane has 98% rejection at 65 pounds.
chipmunkofdoom2
Always Making Something
Understood. This is one of the few cases where such a high capacity might make sense.
Your rejection rate will most likely drop when feeding the brine from membrane 1 into membrane 2, so be sure to account for more DI resin use when you are crunching the numbers to see if this system is worth it. Also keep in mind you'll have twice the membrane replacement costs as well.
As long as you consider those two factors and run an appropriate waste to product ratio with appropriate feed pressure, there shouldn't be any reason why two 150 GPD membranes wouldn't work.
WVNed
The fish are staring at me with hungry eyes.
I saw on here the best way to do this was to install the 2 membranes in parallel with 2 flow restrictors of the original size one ahead of each membrane.
I have 2 75gpd membranes and my TDS readings are the same as when I had 1. The rejection rate is the same.
I have 2 75gpd membranes and my TDS readings are the same as when I had 1. The rejection rate is the same.
WVNed
The fish are staring at me with hungry eyes.
Sorry after the membrane. I admit I didn't do mine that way. I installed the BRS kit by the directions using the original flow restrictor.
My memory has gone blank. There is someone on here that sells these things for a living.
It was his suggestion. He also said you could use it the way mine is plumbed if the source water TDS was low. If it is high you dont want the waste from the first membrane as the source of the second.
My memory has gone blank. There is someone on here that sells these things for a living.
It was his suggestion. He also said you could use it the way mine is plumbed if the source water TDS was low. If it is high you dont want the waste from the first membrane as the source of the second.
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WVNed
The fish are staring at me with hungry eyes.
As for pointing out you will use up resin and filters faster, well you are producing twice as much water. So I guess I can expect half the time to replacement.
WVNed
The fish are staring at me with hungry eyes.
Mine is 124 in, 117 into membranes 2 out of membranes and 0 out. I did the upgrade months ago and have been happy with it.
6 gallons an hour is good enough for my 75 gallon tank. I can see where you would want a lot more.
6 gallons an hour is good enough for my 75 gallon tank. I can see where you would want a lot more.
BZOFIQ
5000 Club Member
I was told by Russ (pretty sure that was his name) from Buckeye Fields Supply (great guys BTW) that if one uses 2 membranes in parallel say each 75GPH, to stick to restrictors labeled for 50GPH to produce less of a waste water. My goal at the time I posed the question was not to produce far more water by doubling up on membranes but to produce less waste (rejected water)
Just an FYI.
Just an FYI.
