How many RODI stages for NYC water?

Dylan.N · Aug 20, 2018

I recently moved into an apartment in Queens, NY and buying distilled water from the grocery store is no longer an option (I no longer have a car). I want to get an RODI system but I don't know how many stages I need. Does anyone in NYC have any recommendations?

Nick30G · Aug 20, 2018

That depends. If you have chloramines in your citys water you are going to want a unit with at least 2 carbon blocks on it. If your city only uses chlorines you will be fine with a unit with 1 carbon block.

Less · Aug 20, 2018

http://www.nyc.gov/html/dep/pdf/wsstate17.pdf
looks like NY only uses chlorine, water is usually good in city , my water out of the tap only has a TDS reading of 30 or so.

Dylan.N · Aug 20, 2018

Less said:
http://www.nyc.gov/html/dep/pdf/wsstate17.pdf
looks like NY only uses chlorine, water is usually good in city , my water out of the tap only has a TDS reading of 30 or so.

So do you think I'll be fine with this BRS 4 stage?
https://www.bulkreefsupply.com/4-stage-value-plus-ro-di-system-bulk-reef-supply.html

Less · Aug 20, 2018

Dylan.N said:
So do you think I'll be fine with this BRS 4 stage?
https://www.bulkreefsupply.com/4-stage-value-plus-ro-di-system-bulk-reef-supply.html

I do, get a tds meter and see what you are getting. I am in Westchester and the water is good here as well.

chefjpaul · Aug 20, 2018

Dylan.N said:
So do you think I'll be fine with this BRS 4 stage?
https://www.bulkreefsupply.com/4-stage-value-plus-ro-di-system-bulk-reef-supply.html

Yes you will be fine with that.

I lived in Queens and water sources are excellent in NYC. Now, when we moved to Westchester, I had to add another DI / silica stage.

I burn through sediment so fast out here compared to the city, approximately 3-1

DesertReefT4r · Aug 20, 2018

Get a 3 stage with DI from Spectrapure or BRS and you will be set. Great RODI filters and customer service.

Dylan.N · Aug 30, 2018

Thanks for the help guys. I got the BRS 4 stage with the TDS meter. But the meter says the TDS going into the filter is 2 (0 coming out). How can that be accurate even with NYC water?

KStatefan · Aug 30, 2018

Dylan.N said:
Thanks for the help guys. I got the BRS 4 stage with the TDS meter. But the meter says the TDS going into the filter is 2 (0 coming out). How can that be accurate even with NYC water?

Going into what filter?

Dylan.N · Aug 30, 2018

KStatefan said:
Going into what filter?

I guess that reading is the TDS of the source water before the DI stage. So that means after the RO stage, correct? If that's the case, then I misunderstood the way the meter works. I'd need my own TDS meter to know the TDS of the source water before it goes to the RO stage.

chipmunkofdoom2 · Aug 30, 2018

Dylan.N said:
I guess that reading is the TDS of the source water before the DI stage. So that means after the RO stage, correct? If that's the case, then I misunderstood the way the meter works. I'd need my own TDS meter to know the TDS of the source water before it goes to the RO stage.

No, that is not correct. If the measurement is before the DI, then almost all of your filtration has been done. The RO membrane removes between 96% and 99% of solids from the water. The DI stage polishes up that last few percent. So 2 ppm TDS going into the DI and 0 ppm TDS coming out is exactly what you'd expect.

Dylan.N · Aug 30, 2018

chipmunkofdoom2 said:
No, that is not correct. If the measurement is before the DI, then almost all of your filtration has been done. The RO membrane removes between 96% and 99% of solids from the water. The DI stage polishes up that last few percent. So 2 ppm TDS going into the DI and 0 ppm TDS coming out is exactly what you'd expect.

Thanks for clearing that up. I initially thought the meter read the TDS before it hit any filter. That's why I wasn't sure why it was so low.

chipmunkofdoom2 · Aug 30, 2018

Dylan.N said:
Thanks for clearing that up. I initially thought the meter read the TDS before it hit any filter. That's why I wasn't sure why it was so low.

Full disclosure, I don't have this unit and it's possible that it's hooked up incorrectly. But, from the sound of it, you're measuring before and after the DI. If you purchased this unit here, it says that the meter is before and after the DI stage. So I think you're good

if you want to be sure, you could share pictures of the TDS meter hookups and we can verify

KStatefan · Aug 30, 2018

If you add a TDS meter for incoming water it will let you monitor the performance of your membrane.

Dylan.N · Aug 30, 2018

chipmunkofdoom2 said:
Full disclosure, I don't have this unit and it's possible that it's hooked up incorrectly. But, from the sound of it, you're measuring before and after the DI. If you purchased this unit here, it says that the meter is before and after the DI stage. So I think you're good if you want to be sure, you could share pictures of the TDS meter hookups and we can verify

Yep that's where I bought it. The meter was hooked up out of the box, so I'm sure it's fine.

Breadman03 · Aug 30, 2018

Just out of curiosity, I checked Amazon Prime for DI water...$25/gallon!! You're going to have to do like 4 water changes for your new filter to pay itself off.

Dylan.N · Aug 30, 2018

Breadman03 said:
Just out of curiosity, I checked Amazon Prime for DI water...$25/gallon!! You're going to have to do like 4 water changes for your new filter to pay itself off.

That's crazy high. When I lived on Long Island and had a car, I would get 1 gallon jugs of distilled water for about $1.25/gallon.