Is this DI resin done?

[Djplus1]

I just replaced my RODI filters less than 2 months ago and my DI (BRS) resin already looks like this. Is this about normal? It's a Coralife 50gpd unit, and the original didn't change color for over 6 months I think.

 

If it's not done yet, how much longer do I have? I make 15 gallons of water a week, though I did make a few extra water changes over the last 2 weeks.

[zygote2k]

check your TDS meter

[Djplus1]

It reads 20. Time for a change, I guess. Is this common to change DI resin so quickly? 

[flooddc]

It's should not go that quick. Either your membrane is exhausted or faulty. When the last time you change your membrane? 

[howaboutme]

Yeah, the DI, especially a new one, will clean up anything left behind from your RO. Something's not right. Calibrate your TDS meter. Is it handheld? You should measure your TDS after your RO (after letting it run for a minute). If your TDS is high, you need to change your RO. The RO should take out 90% or more (I don't remember the exact percentage) of your tap TDS. Your sediment and carbon filters should be changed roughly every 6 months but they do not affect the TDS readings. I've heard that good RO's should last close to 2 years. But even if your RO is not pulling it's weight, a new DI should be cleaning it up and turning 0 TDS water.

[Djplus1]

It's a Coralife 50GPD used less than 1 year. I replaced everything but the membrane in mid April. I performed a membrane flush per the manufacturers directions at the same time. In theory, this thing should be running like a two month old unit.

[hypertech]

Are you sure you got it back together right after the flush? Sometimes when DI exhausts that fast the membrane isn't seated or there is some routing problem so unfiltered water is hitting the DI.

[Djplus1]

It's on right. I double checked everything. It did read zero on my TDS when I did it.

[howaboutme]

 I replaced everything but the membrane in mid April.

 

Check your TDS after the RO (before the DI). When you do this, make sure the unit has been running for at least 30 seconds, if not a minute before you take the measurement. If it reads anywhere high, say above 15 TDS (for example, mine is 9) you should replace the RO membrane.

 

Oh..and regarding the color, mine changed colors pretty fast after initial use but just at the bottom. Then the color change slowed down. Did you put the DI right in after you opened it up? If the DI is exposed or not stored properly, it will almost be rendered useless (from what I've read)....

[Djplus1]

Check your TDS after the RO (before the DI). When you do this, make sure the unit has been running for at least 30 seconds, if not a minute before you take the measurement. If it reads anywhere high, say above 15 TDS (for example, mine is 9) you should replace the RO membrane.

 

Oh..and regarding the color, mine changed colors pretty fast after initial use but just at the bottom. Then the color change slowed down. Did you put the DI right in after you opened it up? If the DI is exposed or not stored properly, it will almost be rendered useless (from what I've read)....

This is what I put in. http://www.bulkreefsupply.com/catalog/product/view/id/165/

All at once. Nothing sat around more than the time it took me to put it in. I will have to check the RO line tomorrow. I am all fished out today as it's been one thing after another this week.

[Djplus1]

Say I need a new membrane, will this work?

http://www.bulkreefsupply.com/catalog/product/view/id/844/

I have the Coralife Pure Flo 2 50gpd, but most of the reviews on this membrane are for people "upgrading" their 50's from other brands anyway. Has anyone used this in a non BRS RO/DI unit? Are they all the same anyway?

[howaboutme]

I wouldn't worry about buying anything for now until you've figured out what the issue is. That particular RO membrane has a higher GPD, which means you'll need to get a new flow restrictor to make it work.

 

Personally, I wouldn't buy any RODI stuff from BRS. They sell those 5 micron filters, which don't last as long and won't get rid of chloramines (not sure if you have that but fairfax does), like they were top end products...Don't get me wrong, I love BRS for all other things.

 

Stick with Air Water Ice (forum sponsor), Purely H20 (what I have), Buckeye Field Supply or Spectrapure, amongst a few others....and next time get 1 micron or less carbon and sediment filters. They will save your RO membrane and will make it last longer...

 

Besides testing after RO, calibrate your TDS meter.  You can use distilled water at 0 TDS...If the RO reads somewhere close to the 20ppm you read after the DI, then it looks like your DI is bad or not properly installed.

[Djplus1]

I wouldn't worry about buying anything for now until you've figured out what the issue is. That particular RO membrane has a higher GPD, which means you'll need to get a new flow restrictor to make it work.

 

Personally, I wouldn't buy any RODI stuff from BRS. They sell those 5 micron filters, which don't last as long and won't get rid of chloramines (not sure if you have that but fairfax does), like they were top end products...Don't get me wrong, I love BRS for all other things.

 

Stick with Air Water Ice (forum sponsor), Purely H20 (what I have), Buckeye Field Supply or Spectrapure, amongst a few others....and next time get 1 micron or less carbon and sediment filters. They will save your RO membrane and will make it last longer...

 

Besides testing after RO, calibrate your TDS meter.  You can use distilled water at 0 TDS...If the RO reads somewhere close to the 20ppm you read after the DI, then it looks like your DI is bad or not properly installed.

Thanks for the tips. I will screw around with this stuff in the morning. You're saying I can calibrate on distilled at 0? I have some 342 ppm TDS solution, though I recall not being able to read 342 when I last used it.

[howaboutme]

You're saying I can calibrate on distilled at 0? I have some 342 ppm TDS solution, though I recall not being able to read 342 when I last used it.

 

I asked the exact same question about 3 months ago and some nice members were able to give me a subtle hint regarding calibrating a TDS (and ph) meter. The informative thread is here:

 

http://wamas.org/forums/topic/56486-looking-for-calibration-fluid-locally/

[Djplus1]

Ok, just got around to testing everything. 

Tap: 135

After Membrane: 27

After DI: 20

 

So is the membrane likely the culprit?

[flooddc]

Ok, just got around to testing everything. 

Tap: 135

After Membrane: 27

After DI: 20

 

So is the membrane likely the culprit?

Is your TDS calibrated? 135 for tab water seem low...I bet you TDS is off.

from you #...seem like DI 

Edited June 18, 2013 by flooddc

[zygote2k]

Check your TDS after the RO (before the DI). When you do this, make sure the unit has been running for at least 30 seconds, if not a minute before you take the measurement. If it reads anywhere high, say above 15 TDS (for example, mine is 9) you should replace the RO membrane.

 

Oh..and regarding the color, mine changed colors pretty fast after initial use but just at the bottom. Then the color change slowed down. Did you put the DI right in after you opened it up? If the DI is exposed or not stored properly, it will almost be rendered useless (from what I've read)....

Here's the proper procedure for TDS monitoring and cartridge replacement:

The "in" sensor is to be placed before water enters the  r/o unit.

The "out" sensor is to be placed after the DI.

When the out TDS reading is greater than 10% of the in TDS reading, it's time to change the prefilter and carbon block. If TDS reads higher than 5% after this procedure, change the DI resin.

If you still have 5% or more after the above steps, replace the membrane.

Membranes typically last 1000-5000g depending on your local water chemistry.

[howaboutme]

Is your TDS calibrated? 135 for tab water seem low...I bet you TDS is off.

from you #...seem like DI 

 

My TDS for tap is 146, fairfax county so it doesn't seem off to me.

 

Here's the proper procedure for TDS monitoring and cartridge replacement:

The "in" sensor is to be placed before water enters the  r/o unit.

The "out" sensor is to be placed after the DI.

When the out TDS reading is greater than 10% of the in TDS reading, it's time to change the prefilter and carbon block. If TDS reads higher than 5% after this procedure, change the DI resin.

If you still have 5% or more after the above steps, replace the membrane.

Membranes typically last 1000-5000g depending on your local water chemistry.

 

Thanks Rob. It sounds like he has a handheld though, which I think are more reliable as you can directly test after RO rather than using percentages. With that said, everything that I've researched says that a good DI can clean up a TDS of 27 after the RO, the DI just won't last very long. So it seems like the RO need to be replaced, I think we agree on that. Then he should test and if it's 0, bingo. If not, then DI is at fault too.

[Djplus1]

Is your TDS calibrated? 135 for tab water seem low...I bet you TDS is off.

from you #...seem like DI 

Tap

Calibration Fluid

 

I'm pretty sure it's fine.

[Djplus1]

My TDS for tap is 146, fairfax county so it doesn't seem off to me.

 

 

Thanks Rob. It sounds like he has a handheld though, which I think are more reliable as you can directly test after RO rather than using percentages. With that said, everything that I've researched says that a good DI can clean up a TDS of 27 after the RO, the DI just won't last very long. So it seems like the RO need to be replaced, I think we agree on that. Then he should test and if it's 0, bingo. If not, then DI is at fault too.

So is it possible that the membrane flush I did 2 months ago "ruined" the membrane? AS I said earlier, I was on the phone with the manufacturer doing a step by step and I know it was done properly.

 

If that's the case, I don't see myself flushing anymore membranes as the first DI cartridge lasted much longer than 2 months and that was a coralife unit, so I'm sure it wasn't all that nice.

[xabo]

here's how I have mine setup:

 

 

[Integral9]

What you are describing sounds familiar.   I had a similar issue before I installed a Chloramin stage filter on my RO unit.   Essentially Chloramines, if not filtered out, will destroy your membrane over time.  Do you have a chloramine filter ("Activated Carbon")?  It kinda looks like a DI canister, but is filled w/ carbon.   Should be placed after the sediment filters, but before the RO filter (you don't want sediment to clog it up).   I have no idea how long it lasts.   I've been using mine for about 2 years now.

[Djplus1]

What you are describing sounds familiar.   I had a similar issue before I installed a Chloramin stage filter on my RO unit.   Essentially Chloramines, if not filtered out, will destroy your membrane over time.  Do you have a chloramine filter ("Activated Carbon")?  It kinda looks like a DI canister, but is filled w/ carbon.   Should be placed after the sediment filters, but before the RO filter (you don't want sediment to clog it up).   I have no idea how long it lasts.   I've been using mine for about 2 years now.

How do you know if you have chloramines?

[Origami]

Your water company can tell you if they use chloramines and, if they use it seasonally, how you get information about when they switch over to it and away from it.

 

Technically speaking, chloramine (NH2Cl) is not filtered out by activated carbon, but the carbon acts as a catalyst to break it down as follows:

 

NH2Cl + H2O + C* ==> NH3 + Cl + H + CO*

2NH2Cl + CO* ==> N2 + 2Cl + 2H + H20 + C*

 

Where the asterisk helps you track the activated carbon used as a catalyst. It's the intermediate ammonia product (NH3) that can cause damage to your RO membrane (it can degrade polyamide-type membranes). Thus, to mitigate the damage, you want to extend the contact time with the carbon so that more of the ammonia is converted through the second reaction.

[xabo]

"Your water company can tell you if they use chloramines and, if they use it seasonally, how you get information about when they switch over to it and away from it".

 

Kinda' like Ethanol is gasoline?