DOW 75gpd HI-Silicate RO membrane

[Zoajohn]

I have a BRS 4 stage unit and am thinking about replacing my membrane. I saw Marine Depot carries this particular membrane, which is different than the one BRS sells. Is it compatible with the BRS, and is it better than a normal membrane?

 

[Zoajohn]

Bump

 

[fcmatt]

Yes. It will work in the BRS RO/DI unit as long as it is a 75 gpd BRS unit. Replacing them is pretty easy.

As for it being better... it appears it is better for removing high amount of silicates. Are you having a problem with silicates? They make a test kit for it btw.

Interesting how marine depot has the pics swapped on the 100 and 75 membranes. Almost did not notice that but should not matter.

 

[Zoajohn]

Yes. It will work in the BRS RO/DI unit as long as it is a 75 gpd BRS unit. Replacing them is pretty easy.

As for it being better... it appears it is better for removing high amount of silicates. Are you having a problem with silicates? They make a test kit for it btw.

Interesting how marine depot has the pics swapped on the 100 and 75 membranes. Almost did not notice that but should not matter.

It caught my eye as being advertised for better silicate removal. The model number on BRS is BW30-1812 as opposed to TW30-1812 on MD.

According to DOW’s catalog the letters stand for “Brackish water” and “tap water” respectively. Wondering if there’s enough of a difference between the two for it to matter.

 

[fcmatt]

Dow is a good company. I would trust their claims. The question is does your source water have an issue? What is the tds from the source?

 

[Zoajohn]

Dow is a good company. I would trust their claims. The question is does your source water have an issue? What is the tds from the source?

I trust as well. The water from my laundry line (which i’d assume is the same as tap?) has TDS of 40 which is super nice. I’m just getting to the point of replacing my membrane since it’s a little more than 2 years old now.

 

[fcmatt]

TDS of 40 is absolutely amazing. Mine is about 350. I would get the cheapest DOW membrane I could. Standard kind.

 

[fcmatt]

Oh btw. I test my tds at 4 points in my ro/di system. If your TDS coming out of the RO side is below 4.. there is absolutely no reason to spend any money yet on a membrane. If I had to guess the water coming out of your RO side is prob 1-3.

I then use two containers of color changing DI on that side for ease of replacement. Super polished water. No wasting DI resin. Rotate them.

So if you want to spend any money that is a sweet setup to aim for. Many do it that way.

 

[Zoajohn]

Oh btw. I test my tds at 4 points in my ro/di system. If your TDS coming out of the RO side is below 4.. there is absolutely no reason to spend any money yet on a membrane. If I had to guess the water coming out of your RO side is prob 1-3.

I then use two containers of color changing DI on that side for ease of replacement. Super polished water. No wasting DI resin. Rotate them.

So if you want to spend any money that is a sweet setup to aim for. Many do it that way.

I only test at the intake, and after DI. I probably should’ve put the OUT TDS after RO. I am getting zero TDS though.

 

[fcmatt]

I guess the best investment at this point is another tds meter that can test 2 points. It will tell you when to spend money on other aspects of the system.

But to be honest.. spending money is fun for new toys but it truly sounds like you are just fine. Just watch output reading from di. No need to spend any money at all.