PDA

View Full Version : Piggyback Upgrade 90 to 180 gpd


Dr Colliebreath
03/04/2015, 07:06 PM
I added the piggyback kit to my existing 5 station ro/di unit (sediment, carbon, membrane, and 2 di) because my water production has been too slow even with new filters. My incoming water temp is around 44 degrees F and pressure is 69 psi (I have the Aquatec booster pump). Even with new sediment and carbon cartridges and membranes (but not di, which was replaced in September), the unit only produces a bit more than 3 gph. Is that right for this water temperature and pressure? It is only about half the rated capacity of the unit.

My production output is about 200 ml per minute and the waste output is around 1,100 ml per minute. Should I shorten the water restrictor? The instructions don't seem to recommend shortening it at that low production and I thought shortening the restrictor increases the waste water ratio.

My gauges show source tds of 347 (unusually high - normally is 150-200 tds). The membrane output is 9 tds.

Is there anything I should change or adjust?

Thanks,

Frank

Dr Colliebreath
03/05/2015, 08:42 PM
Looking at the chart in the sticky How to Calculate Membrane Production, at my temperature the membrane should produce 55% of its rated capacity or a bit more with the increased pressure and lower tds. Thus, my system is producing 25% less than the membrane's rating. Does this have anything to do with the higher waste water to production ratio?

Thank you.

SpectraPure
03/23/2015, 12:46 PM
If the waste to product is too high then I t can effect the membranes performance. How many ml/min is the product and waste?

Jeremy

Dr Colliebreath
03/30/2015, 07:35 PM
Jeremy,

The product is 210 ml/minute and the waste is 1100 ml/minute.

Thanks,

Frank

SpectraPure
03/31/2015, 04:02 PM
Ok we need to test each membrane individually. We need a 2 way ball valve. What we do is bypass 1 membrane. Use the ball valve as the flow restrictor. We get the single membrane performing by itself with a waste to product ratio 3:1.

Test the TDS coming out of the membrane after 30 minutes of running. Then we do this with the other membrane. It would be easier to take the membrane out of the housing and put the other one in the test configuration.

Please tell me what each membranes TDS is producing, and how many ml/min the product and waste are. Set the booster pump to 60 psi.

If any of this is unclear please let me know.

Jeremy

Dr Colliebreath
03/31/2015, 08:28 PM
Thanks, Jeremy. I will do the test over the weekend and report back.

Frank

SpectraPure
04/01/2015, 10:03 AM
Ok! This will tell us that maybe if one of the membranes are not doing well. When you added the piggyback kit did you order a new membrane for your original membrane? When is the last time that your orig membrane was replaced?

General Hardness of the tap water would be ideal to know.

Good luck

Jeremy

Dr Colliebreath
04/05/2015, 10:30 PM
Jeremy,

I also installed a new membrane in the original housing when I added the piggyback kit at the beginning of March. So far, I have run about 115 gallons of product water since installing the two new membranes. I installed new sediment and carbon filters at that time but kept both existing di cartridges.

TDS into the membrane is 143 and the water temperature is 55 deg F. The water pressure with booster pump is 60.

The test results are (in ml/minute):

TDS Out of Membrane Product water Waste water

Membrane 1 1 120 1100
Membrane 2 3 106 1100


The general water hardness is 50-175, with a yearly average of 125 mg/L as reported by the public water authority.

Thanks,

Frank

SpectraPure
04/13/2015, 04:27 PM
Dr

Can you let everyone know what we talked about on the phone for the sake of piggybackers on the piggybacking?!

Jeremy

Dr Colliebreath
04/15/2015, 10:10 PM
Ok, back from taxes.

My system is flowing about 10:1 (waste to product water) and should be around 4:1. Jeremy had me test each membrane by hooking it up in the rodi unit separately and restricting the waste water output (yellow line) with a ball valve. Using a booster pump, the water pressure into the system is 60 psi.

I restricted the output on each membrane from 1100 ml/min to 800 ml/min. The amount of good product water being produced remained the same despite the restriction of water exiting the yellow tube - one membrane produced around 110 ml/minute of good product water and the other membrane produced around 150 ml/minute. The production of good product water did not increase when I closed the ball valve even further and took the waste water flow down to 400 ml/min.

With the piggyback kit installed and water flowing through both membranes, waste water was 1050 ml/min, and good product water was 250 ml/min.

Thus, restricting the waste water output, which presumably increases water pressure against the ro membrane, did not lead to an increase in water getting through the membrane. If I understood Jeremy correctly, this likely means that the membranes are both not working properly. The next step is for me to send the membranes to Jeremy for him to test and confirm.

I ordered the piggyback kit and second new membrane towards the end of February and installed them in the middle of March (along with new sediment and carbon filters). From the outset, the membranes did not flow as much water as should be obtained from a 180 gallon per day system (around 7 gallons per hour). I initially attributed this to how cold the water was coming into my house at the time (about 44 degrees), but that apparently isn't the case. I did 2 water changes and made some top-off water, and have run approximately 125 gallons of good product water through the membranes.

SpectraPure
04/20/2015, 01:59 PM
Dr. Email me your contact info again.

[email protected]

Jeremy

Dr Colliebreath
04/21/2015, 10:25 PM
Jeremy,

I just resent my email with contact information. The email has "Jeremy" as part of the subject line.

Thanks,

Frank

SpectraPure
04/22/2015, 11:27 AM
Thanks

Dr Colliebreath
05/17/2015, 10:09 PM
Jeremy,

I see no material change after obtaining a new pair of membranes as their production is about the same as the old membranes. I have spent hours testing and am unable to see anything in my system that would reduce the product water output so significantly. If my calculations are correct, I am getting about 15% less than the rated output after applying the temperature correction factor. I will send you an email with my contact information so we can get this worked out.

This past weekend, my setup was tap water through the sediment and carbon filters to a single membrane housing with the output going to the product and waste water lines. Tap water pressure was 60 psi with booster pump and the output was about 2700 ml/min coming out of the sediment and carbon filters, so no restriction there. The temperature of the water was 66 degrees F and the TDS of the tap water was 186, both per my Hanna COM100. I bypassed the DI cartridges, so there was no restriction from them. In other words, I took water straight to the membrane and out for measuring. I checked to make sure none of the hoses or fittings were partially blocked (pulled them all apart). I ran my tests through each membrane housing separately and obtained the same results to make sure the housings weren't affecting the results.

My results are:

New membrane 1 - 160 ml/min product water with TDS out of 3
New membrane 2 - 180 ml/min product water with TDS out of 2.5
Old membrane 1 - 140 ml/min product water
Old membrane 2 - 170 ml/min product water

The waste water was 1100 ml/min in all cases. I used the flow restrictor from the 180 gal/day piggyback kit (uncut).

Based on this, and if I am doing the calculations correctly, the system seems to be putting out 118 gal/day with the old membranes and 129 gal/day with the new membranes when it should be putting out 149 gal/day (180 gal/day * 83% correction factor.

Please call me to discuss.

Thanks.

SpectraPure
05/18/2015, 12:04 PM
Please email me many pictures of all angles of your system. Your flush valve isn't open by chance is it?

[email protected]

Dr Colliebreath
05/18/2015, 11:47 PM
Jeremy,

I sent the pictures. Per your request, I also ran the membrane at 2:1 using a ball joint to restrict the output from the yellow waste water line.

My results are (in ml/min):

Old membrane 1 - 160 product, 400 waste
Old membrane 2 - 210 product, 400 waste

New membrane 1 - 200 product, 400 waste
New membrane 2 - 200 product, 400 waste

These tests, like yesterday's tests, were run with water going from the tap to the sediment and then the carbon filters, then to the booster pump, then to the membrane in, and finally out of the membrane through the blue product and yellow waste lines. The DI cartridges are bypassed (not hooked up).

I do not have and have not had the flush valve hooked up for all of the testing we have done.

The water restrictor has a dab of green paint and is 12.5" long (it came with the piggyback kit).

All 4 membranes have the 0090 designation.

The only thing I haven't checked is the pressure gauge.

Thanks,

Frank

SpectraPure
05/19/2015, 10:19 AM
Frank,

Have you adjusted the booster pump to increase the pressure? Also what is the water temp. what are the tds reading at 2:1?

JEremy

Dr Colliebreath
05/19/2015, 11:29 AM
Jeremy,

I will increase the booster pump so that the pressure gauge reads 70 instead of 60 and retest this evening. The house water pressure from the tap is consistent with my readings over many years (42 psi) so I imagine the 60 psi reading with the booster pump is accurate.

The water temp is 66 and tds from the tap 186.

Frank

SpectraPure
05/19/2015, 11:57 AM
Also all four tds readings please.

JEremy

Dr Colliebreath
05/19/2015, 11:42 PM
Jeremy,

Here are the results from my testing on Tuesday evening (in ml/min):

1. Results with booster pump pressure set at 70 psi:

Old membrane 1 - 150 product, 1100 waste, 5.2 tds
Old membrane 2 - 200 product, 1100 waste, 4.1 tds

New membrane 1 - 200 product, 1100 waste, 3.1 tds
New membrane 2 - 200 product, 1100 waste, 3.1 tds


2. Results with booster pump pressure set at 70 psi plus waste water ball valve restricting flow to 2 waste:1 product, which boosted the pressure more

Old membrane 1 - 170 product, 400 waste, 7.3 tds, 75 psi
Old membrane 2 - 220 product, 400 waste, 5.1 tds, 78 psi

New membrane 1 - 220 product, 400 waste, 3.6 tds, 80 psi
New membrane 2 - 220 product, 400 waste, 3.6 tds, 79 psi


During these tests, the tap water tds was 206 and the tap water temperature was 67 degrees F.

These tests, like the tests of the prior two days, were run with water going from the tap to the sediment and then the carbon filters, then to the booster pump, then to the membrane in, and finally out of the membrane through the blue product and yellow waste lines. The DI cartridges are bypassed (not hooked up), the flush valve isn't hooked up, etc. I ran only one membrane at a time.

Thanks,

Frank

SpectraPure
05/20/2015, 10:37 AM
Those membranes are doing awesome at 2:1. We need to hook the flush valve back up. Everything looks good in my eyes my friend individually, but lets get it all back together to see what its doing as a unit.

What is your general hardness of your tap water?

Jeremy

Dr Colliebreath
05/20/2015, 09:08 PM
Those membranes are doing awesome at 2:1. We need to hook the flush valve back up. Everything looks good in my eyes my friend individually, but lets get it all back together to see what its doing as a unit.

What is your general hardness of your tap water?

Jeremy

I will set the system back up completely and obtain test readings, but neither the "old" membranes put in service in the middle of March (less than 200 gallons of production) nor the more recent "new" membranes (only run for testing purposes) meet the 99% rejection standard, right?

The general water hardness is 50-175, with a yearly average of 125 mg/L as reported by the public water authority.

SpectraPure
05/21/2015, 11:08 AM
Can you obtain your water quality report from 2014, or possibly from this year? Sodium will hinder membranes rejection. The rejection should also peak in the summer when the nominal water temperature of 77 degrees is back. 98.2 is pretty good. Perhaps moving the waste ratio to 2.5:1 will net better tds.

JEremy

Dr Colliebreath
05/21/2015, 11:11 PM
Jeremy,

Per the 2014 water quality report, the sodium is 25.3 mg/L and they show a range of 10-120. I emailed you a link to the report so you can see the entire report.

I ran the unit fully hooked up at 68 psi with the "old" membranes that were put in place in early March and have less than 200 gallons run through them. I used the ball valve to restrict the waste water and obtained the following results:

Product water 320 ml/min, waste water 1,000 ml/min, and tds of 3 for the combined membrane output (from the DM1 gauge on the rodi unit). The tap water tds today is 179 and the temperature of the water is 68, and the pressure was 70 psi. This is 121 gallons per day but it should be 155 gallons per day applying the temperature correction factor (and really it should be in excess of 175 gallons per day due to the higher pressure being used).

The only thing that hasn't been changed is the water restrictor but it isn't apparent how that could be a problem. Further testing doesn't seem like it will turn up anything new and based on all of the Spectrapure advice I have seen the life of the membranes will be reduced if I run them at 2:1 or 2.5:1.

At this point, what should I do? Should I just return the second set of membranes (used only for testing starting in early May) and live with the lower output?

Thanks,

Frank

SpectraPure
05/29/2015, 11:48 AM
Frank,

The membranes don't always do 99% in all locations. Membranes do not reject sodium very well at all. IT is the one thing they really have trouble with. Your 98.2% rejection was pretty good. At this point I think we are trying to chase a ghost. Keep both sets of membranes, and use the 2 of the 4 that is better than the other 2.

Jeremy

Dr Colliebreath
06/01/2015, 09:39 PM
Jeremy,

I agree it is unlikely that we will get improved performance at this point. I purchased two membranes at the end of February. You had me purchase a second pair of membranes in the middle of March with the thought that the first two might have been defective and I would return them to Spectrapure for a refund. The second set of membranes proved to be only slightly better than the first set and have only run a couple of gallons through them for testing purposes.

My point is that I need to return the second pair of membranes for a refund or I will have paid for 4 membranes when I will only use two. I have no use for an extra set given how long the first set will last. I infer there is no more testing to do, so please confirm that I should return the second set of membranes.

Thank you.

SpectraPure
06/02/2015, 05:20 PM
Oh I see.

Send them in
2167 E. 5TH ST
TEMPE, AZ 85281

Dr Colliebreath
06/03/2015, 09:46 PM
Will do, Jeremy, thanks.

Frank

SpectraPure
06/04/2015, 10:44 AM
keep the two best ones.

Jeremy

Dr Colliebreath
06/10/2015, 08:07 PM
Jeremy,

I applied for a RMA number and haven't heard yet. Should I just send them in without the RMA?

Thanks for all of your assistance,

Frank

SpectraPure
06/11/2015, 11:10 AM
Frank,

Your rma number is RMA-JEREMY54. Yes please keep the best two membranes, and send me the others back.

Jeremy

Dr Colliebreath
06/11/2015, 11:00 PM
Jeremy,

Thanks, will do.

Your guidance helped me learn a lot about the details of how the system works.

SpectraPure
06/15/2015, 10:21 AM
Frank,

Thank you very much. I do what I can! Please let me know if there is anything else that you may need help with.

Jeremy