Do I need an RO/DI booster?

[zalick]

Where have you guys seen a standard size membrane rated above 100gpd at 50-60psi? To achieve 150 and 200gph every consumer system uses either TWO 75 or 100gpd membranes. It's a Melev reefs system which should be no different. Something is out of wack if ANY single membrane unit is producing that fast at 50psi that is concerningly fast even with a booster pump.

Agreed 100%. Mine is a 180gpd spectrapure and it's two 90gpd. I have a booster to keep it right at 80psi and manually adjust the waste water to achieve 2:1. I've run 18,000 gallons through these membranes and rejection is still 99.9%.

Something is way off here... I'm wondering if chlorine damaged the membrane at some point so it's allowing more water through??

 

[zalick]

So should I be concerned about my water quality at all? Like I said, I’m still new to this, but I regularly check my TDS after the DI. Just replaced the resin today

Your membrane is probably shot.

I just looked up your membrane. It's rated at 100gpd at 60psi and 77 degrees F with a rejection rate of 98%. Since you are getting 150gpd at 50psi and presumable colder than 77f and a rejection rate of 90% or less, the membrane needs to be replaced. You'll burn through way more $$$ in DI resin if you don't.

I've processed 17,000 gallons though my two 90gpd and the rejection is still 99.9%. Haven't change my DI resin in a LONG time.

That membrane is about $40 online.

https://www.lenntech.com/Data-sheets/CSM-RE2012-100-L.pdf

 

[riche]

You can put a valve on the waste line and manually adjust it to set your waste water rate, instead of relying on a flow restrictor. Just am FYI.

I have a question in regards to this. If I adjust my Valve on teh waste water, if I adjust eh waste water to slow it down I get hardly any good water coming out. I have to turn it almost all the way open to get a good flow of good water. Is this a Pressure issue?

 

[KStatefan]

I have a question in regards to this. If I adjust my Valve on teh waste water, if I adjust eh waste water to slow it down I get hardly any good water coming out. I have to turn it almost all the way open to get a good flow of good water. Is this a Pressure issue?

what is your pressure?

 

[riche]

between 50 and 55 psi

 

[KStatefan]

between 50 and 55 psi

That should work fine a Filmtech membrane is rated at 50 psi

 

[Reef.]

between 50 and 55 psi

time how long it takes to make 1 gallon of rodi water, multiply that time by 24 if it would take longer than 24 hours to make the amount of water your membrane is rated to, then you would benefit from a booster.

If you are happy with how long it take regardless then no need for the booster, just keep in mind the boost will also increase the efficiency of your membrane, so prolong your resin.