RODI isues??

Saltydrip · 12/06/2012, 07:12 PM

I live in an old farm house built in 1707. The only place to put the rodi is in the basement where there is a dirt floor and no drains. I ran a 1/4" line about 25 feet out the back door where it just drains downhill into my pond. Problem is that I'm only getting about a little over a gallon an hour. Not cool. Its saposed to be a 75gpd unit so I should be getting closer to 3-3.5.

Could it be because of the long waste drain line??

Also this unit has color changing resin and the bottom 3/4" of the resin is already changing tan! I knew my water was bad but that seams unreal!

downbeach · 12/06/2012, 07:18 PM

What is the pressure of your water source? You need a minimum of 50 psi to get near the rated amount of your membrane. Do you know what the TDS is coming out of the RO membrane?

Saltydrip · 12/06/2012, 07:34 PM

I did find a kink in the line so that fixed the gpd rate. Just doubled production!!

But the membrane is still changing color a lot faster than I would ever gues. 10 gallons of RODI and about an inch and a half of the membrane is tan.

We don't drink our tap water r even give it too the dogs. It's bottled all around. It has a rather metallic taste.

Buckeye Hydro · 12/07/2012, 12:35 PM

If you starved the RO membrane for pressure, it would have produced not so clean water, which would exhaust the DI quickly.

Russ

Saltydrip · 12/07/2012, 04:20 PM

Water source is only 48psi.

Does this mean I need a booster pump?

fishgate · 12/07/2012, 06:21 PM

Membrane? I think you are looking at the DI resin. The membrane is usually sealed and on the top of the RODI setup. You need to get a TDS meter and see how much you have before and after the TDS.

This one.

http://www.amazon.com/HM-Digital-DM-...S-DM1-0-9990-4

Saltydrip · 12/07/2012, 06:26 PM

I made a few adjustments. My water system says max psi is 60 so I bumped it up to 55. I'm now getting water at at 5gal in 1hour 45min. Sounds about right. I'll get a TDS meter asap. I ran the usual tests and got zeros across the board with a FW kit but it's about a year and a half old do I font trust it 100% but it has to be beter than the bottled water I have been using. Sometimes I could tell by the looks of my corals if the water was an inferior batch.

Saltydrip · 12/07/2012, 06:32 PM

[QUOTE=fishgate;20966016]Membrane? I think you are looking at the DI resin. The membrane is usually sealed and on the top of the RODI setup. You need to get a TDS meter and see how much you have before and after the TDS.

My bad I meant resin. I'm a newb to these things. I plan on ordering one asap. Thanks for the link, that helps.

Buckeye Hydro · 12/08/2012, 04:34 AM

Quote:

Originally Posted by Saltydrip

My water system says max psi is 60 so I bumped it up to 55.

Sorry but I don't understand. What "water sytem" are you talking about?

How are you "bumping pressure?"

Russ

Ron Reefman · 12/08/2012, 04:39 AM

Quote:

Originally Posted by BuckeyeFS

Sorry but I don't understand. What "water sytem" are you talking about?

How are you "bumping pressure?"

Russ

Russ,
What is the optimum water pressure for a 75gpd membrane?
Thanks

Buckeye Hydro · 12/08/2012, 05:08 AM

The "optimum" pressure for RODI systems seems to be an issue that keeps coming up on RC. There's a few things to consider here, including the best pressure for the membrane, and the pressure ratings for other system components.

Filmtec 75 gpd membranes are spec'ed with a max pressure of 300 psi. In general, the higher the pressure the better the membrane will perform in terms of how fast it produces clean water, and how clean the water is (the rejection curve goes pretty flat however at less than 100 psi). Now, in practical terms, no one has pressure approaching 300 psi in their plumbing. How about if you have a booster pump? Chances are it will max out at 120 psi or less.

I can hear the question already - "I thought the optimum pressure for Filmtec membranes was 50 psi - that's what the manufacturer says." Well, not really. What Filmtec says is that if you provide a 75 gpd membrane feedwater at 50 psi, 77 degrees F, and 250 ppm; and configure the system to run at 15% recovery, it will produce 75 gallons per day, plus or minus 20%, at the spec'ed rejection rate. Is 50 psi the "optimum" pressure? No. It just happens to be one of the standard test conditions used by the manufacturer in their testing. Most membrane manufacturers other than Filmtec use a test pressure of 60 psi.

Remember that your flow restrictor is designed to provide about a 4:1 ratio of concentrate to permeate assuming you have "standard conditions" (50 or 60 psi, 77 degree water, ...). So if you operate your system at much higher pressure, you may have to adjust/change your flow restrictor so that you stay near the recommended 4:1 ratio.

Also be aware that other components in your RO or RODI system can't handle anything close to the 300 psi your membrane can. The weakest link in most systems in terms of ability to withstand pressure is the clear housings. This is why we always recommend installation of booster pumps after the prefilters.

Russ

Saltydrip · 12/08/2012, 10:51 AM

I turned up the water pump on/off pressure regulator. My tank and furnace say 60psi max. I bumped it up to 53psi. Figure that extra 5psi should help. I also ran the RODI waste line a little more flow friendly as well as found a slight kink in the line going from the membrain to the resin canister. Replaced that line and now I'm making water at 5gal in a little under 2 hours. I think I'm good to go now. I will be adding a residential sediment filter in line before the RODI though because my well is rather dirty and I'm always replacing our filter and the RODI is installed befor the home filter.

Buckeye Hydro · 12/08/2012, 11:06 AM

Now I understand. You're on a residential well. That well pump is controlled by a pressure switch. Typically they are set to come on at something like 30 psi, and off at something like 50 psi.

12/06/2012, 07:12 PM	#1
Saltydrip Registered Member Join Date: Jan 2012 Posts: 1,826	RODI isues?? I live in an old farm house built in 1707. The only place to put the rodi is in the basement where there is a dirt floor and no drains. I ran a 1/4" line about 25 feet out the back door where it just drains downhill into my pond. Problem is that I'm only getting about a little over a gallon an hour. Not cool. Its saposed to be a 75gpd unit so I should be getting closer to 3-3.5. Could it be because of the long waste drain line?? Also this unit has color changing resin and the bottom 3/4" of the resin is already changing tan! I knew my water was bad but that seams unreal! __________________ Current tank 48" 75g DT w/ 55g sump/fuge.

12/06/2012, 07:34 PM	#3
Saltydrip Registered Member Join Date: Jan 2012 Posts: 1,826	I did find a kink in the line so that fixed the gpd rate. Just doubled production!! But the membrane is still changing color a lot faster than I would ever gues. 10 gallons of RODI and about an inch and a half of the membrane is tan. We don't drink our tap water r even give it too the dogs. It's bottled all around. It has a rather metallic taste. __________________ Current tank 48" 75g DT w/ 55g sump/fuge.

12/07/2012, 04:20 PM	#5
Saltydrip Registered Member Join Date: Jan 2012 Posts: 1,826	Water source is only 48psi. Does this mean I need a booster pump? __________________ Current tank 48" 75g DT w/ 55g sump/fuge.

12/07/2012, 06:21 PM	#6
fishgate Registered Member Join Date: Oct 2011 Location: Damascus, MD Posts: 3,340	Membrane? I think you are looking at the DI resin. The membrane is usually sealed and on the top of the RODI setup. You need to get a TDS meter and see how much you have before and after the TDS. This one. http://www.amazon.com/HM-Digital-DM-...S-DM1-0-9990-4 __________________ 125RR in-wall, 40B Sump, CS180 BM Skimmer, ATI 4x80 watt, eheim 1262, custom wrap around rock wall, ReefKeeper Elite 120g in-wall, 40B Sump, PC 54wx4, Jabao DC-6000 (full siphon), future seahorse t Current Tank Info: 125g, 120g, 2x40b sumps, ATI 4x80 T5HO

12/07/2012, 06:26 PM	#7
Saltydrip Registered Member Join Date: Jan 2012 Posts: 1,826	I made a few adjustments. My water system says max psi is 60 so I bumped it up to 55. I'm now getting water at at 5gal in 1hour 45min. Sounds about right. I'll get a TDS meter asap. I ran the usual tests and got zeros across the board with a FW kit but it's about a year and a half old do I font trust it 100% but it has to be beter than the bottled water I have been using. Sometimes I could tell by the looks of my corals if the water was an inferior batch. __________________ Current tank 48" 75g DT w/ 55g sump/fuge.

12/06/2012, 07:18 PM	#2
downbeach Registered Member Join Date: Nov 2006 Location: Smyrna, Delaware Posts: 3,767	What is the pressure of your water source? You need a minimum of 50 psi to get near the rated amount of your membrane. Do you know what the TDS is coming out of the RO membrane?

12/07/2012, 12:35 PM	#4
Buckeye Hydro .Registered Member Join Date: Sep 2006 Location: Cincinnati, Ohio Posts: 4,857	If you starved the RO membrane for pressure, it would have produced not so clean water, which would exhaust the DI quickly. Russ

12/07/2012, 06:32 PM	#8
Saltydrip Registered Member Join Date: Jan 2012 Posts: 1,826	[QUOTE=fishgate;20966016]Membrane? I think you are looking at the DI resin. The membrane is usually sealed and on the top of the RODI setup. You need to get a TDS meter and see how much you have before and after the TDS. My bad I meant resin. I'm a newb to these things. I plan on ordering one asap. Thanks for the link, that helps. __________________ Current tank 48" 75g DT w/ 55g sump/fuge.

12/08/2012, 05:08 AM	#11
Buckeye Hydro .Registered Member Join Date: Sep 2006 Location: Cincinnati, Ohio Posts: 4,857	The "optimum" pressure for RODI systems seems to be an issue that keeps coming up on RC. There's a few things to consider here, including the best pressure for the membrane, and the pressure ratings for other system components. Filmtec 75 gpd membranes are spec'ed with a max pressure of 300 psi. In general, the higher the pressure the better the membrane will perform in terms of how fast it produces clean water, and how clean the water is (the rejection curve goes pretty flat however at less than 100 psi). Now, in practical terms, no one has pressure approaching 300 psi in their plumbing. How about if you have a booster pump? Chances are it will max out at 120 psi or less. I can hear the question already - "I thought the optimum pressure for Filmtec membranes was 50 psi - that's what the manufacturer says." Well, not really. What Filmtec says is that if you provide a 75 gpd membrane feedwater at 50 psi, 77 degrees F, and 250 ppm; and configure the system to run at 15% recovery, it will produce 75 gallons per day, plus or minus 20%, at the spec'ed rejection rate. Is 50 psi the "optimum" pressure? No. It just happens to be one of the standard test conditions used by the manufacturer in their testing. Most membrane manufacturers other than Filmtec use a test pressure of 60 psi. Remember that your flow restrictor is designed to provide about a 4:1 ratio of concentrate to permeate assuming you have "standard conditions" (50 or 60 psi, 77 degree water, ...). So if you operate your system at much higher pressure, you may have to adjust/change your flow restrictor so that you stay near the recommended 4:1 ratio. Also be aware that other components in your RO or RODI system can't handle anything close to the 300 psi your membrane can. The weakest link in most systems in terms of ability to withstand pressure is the clear housings. This is why we always recommend installation of booster pumps after the prefilters. Russ

12/08/2012, 10:51 AM	#12
Saltydrip Registered Member Join Date: Jan 2012 Posts: 1,826	I turned up the water pump on/off pressure regulator. My tank and furnace say 60psi max. I bumped it up to 53psi. Figure that extra 5psi should help. I also ran the RODI waste line a little more flow friendly as well as found a slight kink in the line going from the membrain to the resin canister. Replaced that line and now I'm making water at 5gal in a little under 2 hours. I think I'm good to go now. I will be adding a residential sediment filter in line before the RODI though because my well is rather dirty and I'm always replacing our filter and the RODI is installed befor the home filter. __________________ Current tank 48" 75g DT w/ 55g sump/fuge.

12/08/2012, 11:06 AM	#13
Buckeye Hydro .Registered Member Join Date: Sep 2006 Location: Cincinnati, Ohio Posts: 4,857	Now I understand. You're on a residential well. That well pump is controlled by a pressure switch. Typically they are set to come on at something like 30 psi, and off at something like 50 psi.