The new 150GPD FilmTec membrane is excellent

[speakerguy]

I recently purchased an RO/DI system with the new 150GPD FilmTec membrane that claims 98% rejection rate. My initial tests showed my 480PPM tap water knocked down to 11PPM before the DI. The production rate was above the 150GPD specification, but we have very good water pressure and it is quite warm in Texas right now. Recovery rate was 30% RO / 70% waste water.

This is an excellent upgrade when it is time to change out your old 75GPD membrane.

 

[palmerc]

Godo to know. I'm usign a 50gpd Filmtec membrane but my RO production rate is very slow (8-10 hours for 6 gallons of RO) but I suspect low water pressure.

I am willing to sacrifice a little on my TDS for a faster , more efficient RO production rate

 

[speakerguy]

I was getting about 200GPD. It filled a 2 cup pyrex measuring glass in under a minute. 90+ degree weather on the patio with very good water pressure.

 

[palmerc]

Most hobbt grade test kits are quite inaccurate basically cause you dealwith onlt a few drops of reagent to a smallwater volume.

If you interested in more accurate results (at a lowish cost) then try this (stolen form a fellow reefer)

Use 100ml tankwater. Use methyl orange indicator (10 drops). Titrate using a burette with 0,1N HCL till solution turns orange (around 3ml's). Each ml HCl equals 1meq/l or times by 2.8 for result in dkH.

Since you can read in 0.05ml increments easily with a burette, you can get a detection limit of 0.14 dKH

Use other suitable indicators if colour change is not clear.

 

[speakerguy]

Wrong thread palmerc?

 

[palmerc]

Sorry

 

[palmerc]

So what membrane were you using previously Speakerguy to get 200 gpd?

 

[speakerguy]

The new 150GPD membrane is what is giving me ~200GPD under my current conditions, which are much better than most will have re: water pressure and temp. This is a new RO/DI system I just ordered.

My only other experience with an RO system is my under the sink 35GPD unit, which did exactly 35GPD when I tested it last winter. I just moved to a new city and the water here requires RO/DI. At my old location the water was fine right out of the tap for a reef tank (though some here will decry that possibility).

 

[AZDesertRat]

You will not want to run it at much less than 4:1 waste ratio with a tap water TDS of 480 or you will not have it very long. Membranes need to be constantly flushed or the salts begin to build up and solidify on their surface rendering them useless. I would suggest getting either a capillary tube type flow restrictor and trim it for an exact fit or an adjustable one if you have swings in water temperature season to season.
My personal experience with the 150 GPD membrane was a good one too but the vendor I bought it from quit carrying it as they could not get enough of them to pass their bench testing requirements. Sounds like they are hit and miss as far as quality control as since most vendors do not bench test their membranes you would never know unless you perform the testing yourself.