Tds reading on new mebrane

Wolv18 · 11/05/2014, 01:36 PM

HI I was just wondering what is the acceptable levels for tds reading on a new mebrane. I just put in a new mebrane flushed it and let in run for about an hour. I have 92 tds inflow and a consistent 6 tds after the membrane and before the di resin. I've read online it seems like most people have around 2 to 3 tds after the membrane. Thanks.

Shaummy · 11/05/2014, 10:08 PM

What's the rejection percentage of your new membrane? That should help tell you if you are getting an appropriate amount of TDS reduction before the DI.

That said..the TDS you are seeing doesn't seem out of line...I think my system runs about 4-6 TDS out of the membrane, but I've never measured my incoming TDS.

tkeracer619 · 11/06/2014, 09:14 PM

If it is a filmtech 75gpd you can get above 99% rejection but it usually falls somewhere between 96% and 98%.

A lot of bargin membranes will be between 92% and 96%.

You have 93.5% rejection.

1-(Output TDS/Input TDS)= Rejection Rate

Each time you cut TDS in half you ~double the DI life.

Wolv18 · 11/07/2014, 02:18 AM

Yeah it's a brand new film tech, that's why I thought it should be a lower tds

azjohnny · 11/07/2014, 05:40 AM

IMO your rejection rate is unacceptable, I have TDS levels of 675 and out of the membrane is 7ppm.

What is your water pressure? That is critical. Make sure it is at least 60 psi

Wolv18 · 11/07/2014, 12:05 PM

65 when producing water

tkeracer619 · 11/07/2014, 02:03 PM

Re install the membrane to make sure it seated properly then contact the seller for an exchange. If that is what it is producing at 65psi it is a bad membrane.

I like to buy filmtechs from Spectrapure. You can buy them pre tested out at 98% or better.

alton · 11/07/2014, 02:12 PM

Is your water pressure over 50psi? If not that might be one problem, I get mine from Russ which he test before they go out so you know you have a good one

Wolv18 · 11/07/2014, 02:16 PM

I produced 5 more gallons and is settled down to 2 and 3 now I guess I just had to make a a little bit more

azjohnny · 11/07/2014, 05:23 PM

How much water do you usually make at one time?

What rejection ratio is the flow restrictor set at?

You might want to get a flush system for the filter

Your TDS should be 1ppm. By improving the TDS of the good water from 3ppm to 1ppm will double the life of your DI

Wolv18 · 11/07/2014, 07:40 PM

I just started making water so this I've made about 15 gallons. I threw out the first 10 gallons, and I also have a flush kit on the system as well. I flushed the mebrane for about an hour before I started using it. I'm not sure how to check the rejection rate of the flow restrictor.

azjohnny · 11/07/2014, 09:13 PM

You can fill a container of the good water and time it, than using that same time frame fill a container of the waste water. Compare the 2 amounts. I run mine at a ratio of 4/1 waste/good.

Spectrapure has a page on Reef Central with a lot of info in the stickies
http://reefcentral.com/forums/forumdisplay.php?f=229

11/05/2014, 01:36 PM	#1
Wolv18 Registered Member Join Date: Nov 2001 Location: Greensboro NC Posts: 79	Tds reading on new mebrane HI I was just wondering what is the acceptable levels for tds reading on a new mebrane. I just put in a new mebrane flushed it and let in run for about an hour. I have 92 tds inflow and a consistent 6 tds after the membrane and before the di resin. I've read online it seems like most people have around 2 to 3 tds after the membrane. Thanks.

11/05/2014, 10:08 PM	#2
Shaummy Registered Member Join Date: Jul 2001 Location: Chicago burbs Posts: 857	What's the rejection percentage of your new membrane? That should help tell you if you are getting an appropriate amount of TDS reduction before the DI. That said..the TDS you are seeing doesn't seem out of line...I think my system runs about 4-6 TDS out of the membrane, but I've never measured my incoming TDS. __________________ Shaummy Current Tank Info: Current Tank Info: 90g mixed reef, hermits, snails,Lyretail Anthias,Orange back Fairy Wrasse,Blue Reef Chromis,small blue tang, Flame Hawk, Royal Gramma

11/06/2014, 09:14 PM	#3
tkeracer619 Registered Member Join Date: Jan 2006 Location: Westminster, CO Posts: 17,289	If it is a filmtech 75gpd you can get above 99% rejection but it usually falls somewhere between 96% and 98%. A lot of bargin membranes will be between 92% and 96%. You have 93.5% rejection. 1-(Output TDS/Input TDS)= Rejection Rate Each time you cut TDS in half you ~double the DI life. __________________ Hobby Experience: 9200ish gallons, 26 skimmers, and a handful of Kent Scrapers. Current Tank: Vortech Powered 600G SPS Tank w/ 100gal frag tank & 100g Sump. RK2-RK10 Skimmer. ReefAngel. Radium 20k.

11/07/2014, 02:03 PM	#7
tkeracer619 Registered Member Join Date: Jan 2006 Location: Westminster, CO Posts: 17,289	Re install the membrane to make sure it seated properly then contact the seller for an exchange. If that is what it is producing at 65psi it is a bad membrane. I like to buy filmtechs from Spectrapure. You can buy them pre tested out at 98% or better. __________________ Hobby Experience: 9200ish gallons, 26 skimmers, and a handful of Kent Scrapers. Current Tank: Vortech Powered 600G SPS Tank w/ 100gal frag tank & 100g Sump. RK2-RK10 Skimmer. ReefAngel. Radium 20k.

11/07/2014, 02:18 AM	#4
Wolv18 Registered Member Join Date: Nov 2001 Location: Greensboro NC Posts: 79	Yeah it's a brand new film tech, that's why I thought it should be a lower tds

11/07/2014, 05:40 AM	#5
azjohnny Registered Member Join Date: Apr 2012 Location: Gold Canyon Posts: 2,914	IMO your rejection rate is unacceptable, I have TDS levels of 675 and out of the membrane is 7ppm. What is your water pressure? That is critical. Make sure it is at least 60 psi

11/07/2014, 12:05 PM	#6
Wolv18 Registered Member Join Date: Nov 2001 Location: Greensboro NC Posts: 79	65 when producing water

11/07/2014, 02:12 PM	#8
alton Registered Member Join Date: Jan 2005 Location: Zuehl, Texas Posts: 4,460	Is your water pressure over 50psi? If not that might be one problem, I get mine from Russ which he test before they go out so you know you have a good one

11/07/2014, 02:16 PM	#9
Wolv18 Registered Member Join Date: Nov 2001 Location: Greensboro NC Posts: 79	I produced 5 more gallons and is settled down to 2 and 3 now I guess I just had to make a a little bit more

11/07/2014, 05:23 PM	#10
azjohnny Registered Member Join Date: Apr 2012 Location: Gold Canyon Posts: 2,914	How much water do you usually make at one time? What rejection ratio is the flow restrictor set at? You might want to get a flush system for the filter Your TDS should be 1ppm. By improving the TDS of the good water from 3ppm to 1ppm will double the life of your DI

11/07/2014, 07:40 PM	#11
Wolv18 Registered Member Join Date: Nov 2001 Location: Greensboro NC Posts: 79	I just started making water so this I've made about 15 gallons. I threw out the first 10 gallons, and I also have a flush kit on the system as well. I flushed the mebrane for about an hour before I started using it. I'm not sure how to check the rejection rate of the flow restrictor.

11/07/2014, 09:13 PM	#12
azjohnny Registered Member Join Date: Apr 2012 Location: Gold Canyon Posts: 2,914	You can fill a container of the good water and time it, than using that same time frame fill a container of the waste water. Compare the 2 amounts. I run mine at a ratio of 4/1 waste/good. Spectrapure has a page on Reef Central with a lot of info in the stickies http://reefcentral.com/forums/forumdisplay.php?f=229