ro/di help: way to much waste water

[r20crazy]

1st off I have a water general 6 stage, that has all spectrapure guts that were installed 7/09. replaced sediment and dual carbon blocks with .5 micron filters, and a 90gpd with new flow restrictor cut to size for a waste to product ratio of 4.2:1. this allowed me to fill a 5g jug in right around 2 hours. I have noticed a huge decrease in product recently, so started looking into the problems using spectrapures' forum on RC. so I just got done replacing the 3 prefilters listed above, and flushed the membrane, which did NOTHING. my waste to product is currently 8:1!!!! it takes me about 40mins to make a gallon of ro/di right now when I used to get alot more in the same time period.

I'm in socal, and the input water temp is 22C, input tds is ~420ppm, product tds is zero. I am assuming input pressure is unchanged (my unit doesn't have a pressure gage)as the water source is unchanged. what could be going on here? I can hopefully provide any additional info that may be needed. thanks in advance

there's only so may things it could be, I hope its not the 6 month old membrane or flow restrictor. the autoshutoff valve is working properly. :dontknow:

 

[jason142]

Is there a valve going to your waste and is it open all the way. If it is that is probably your problem.

 

[r20crazy]

no, waste is straight dump outa the membrane. only valves are on the unit feed from the sink and product after di. thanks for the idea.....keep them comin'

 

[jason142]

If there is no restriction after the membrane then it is in constant flush and is causing your waste to product ratio to suck. Is your restrictor installed on the waste side of your membrane. The only other thing that I can think of is maybe your DI filter is partially clogged restricting the flow of the product. What is your current TDS of the product?

 

[r20crazy]

product tds is zero. I'm gonna take the unit apart piece by piece today and look for clogs/etc. and yes the restrictor is in correct, as 6ish months ago when it was put in it was working fine with the rcmded wasteroduct ratio. my di canisters ar the smaller clear tubes with the blue caps. I have 3 of them total, I'll check them too.

I noticed as I was getting fustrated and called it quits yesterday, that when I opened the product valve it seemed like one of the di cartrages was 'goin dry', aka I could see the water level going down in it. it was the 2nd one in line if that makes a difference

will update later with hopefully the problem and the solution. thanks again for your help

 

[shapermike]

Is the flow restrictor a the end where the wast water line is leaving the system? The restrictor is used to put back presser on the membrane. If you are getting more wast water it is due to no or low back presser or the incoming water presser is low.

 

[r20crazy]

it is right were the waste exits the membrane. assuming input pressure is unchanged as the unit has not been relocated since it was installed. going to hopefully find a pressure gage right now. again, unit was working fine for almost 6 months until this issue started.

 

[cthetoy]

Your RO/DI will should produce less water the past month or so due to the cooler weather. Even though your input is 22c that because the pipes in your garage is warmer. After a gallon your input temp will be alot cooler.

You should measure the TDS before it hits the DI (after your membrane) as well. A good working unit should reject 98% of your incoming TDS. I have 350 TDS and after the membrane its 7 TDS. You should be around 10 TDS or lower. The lower the TDS you can get before it hits the DI the longer your DI resin will last. The resin is the most expensive part to replace per gallon of water made

 

[r20crazy]

I agree it will produce less, but performing the calculations, with the gpd of the membrane, the temp correction factor, and the input pressure I should still be getting ~2.5g/hr, and I'm getting 1g/hr.

actual gpd=memberane ratred gpd x temp correction factor x (actual input pressure/60)
pluging in the numbers: 90gpd x 0.912 x (45/60) [ASSuming worst case pressure as I can't measure it w/o gage] = 61.56gpd

61.56gpd / (24hrs/day) = 2.565g/hr <---- and I am getting 1g/day

ro/di unit is in house under a sink, not in garage. temp measured is the product temp coming outa the unit. DI has not been changed in over 6 months and tds is still zero.

I was unable to find a pressure gage, but I'm gonna take everything apart and look for anything obvious, since the prefilter changes did nothing

 

[shapermike]

You should measure the TDS before it hits the DI (after your membrane) as well. A good working unit should reject 98% of your incoming TDS. I have 350 TDS and after the membrane its 7 TDS. You should be around 10 TDS or lower. The lower the TDS you can get before it hits the DI the longer your DI resin will last. The resin is the most expensive part to replace per gallon of water made

My unit witch is running the BRS 60 gal membrane does a great job. the TDS in is 750 and out right after the membrane it is around 1~2. I have really hard water where I live.

 

[r20crazy]

some numbers as of right now:

input tds today:465ppm
waste water tds:501ppm
product: 0ppm
tds pre DI: 4ppm

product:waste ratio going thru the complete system 1:8

product:waste ratio outa the membrane (pre di) 1:8

product:waste ratio bypassing flow restrictor 0:100


gonna put in an old 100gpd restrictor (if I can find it) and see what happens, and bypass the autoshutoff to check it

 

[r20crazy]

autoshutoff valve bypassed. still 1:8 [prod:waste]

now to find the old flow restrictor and try that

 

[r20crazy]

something is wrong with the flow restrictor.... replaced it with the one I saved from the old 100gpd membrane and I am now 1:4. maybe its dirty/broken? the one in question is the capilary style that pushes inside the waste water tube. now to find out why it failed... (and check my tds with the 'new' restrictor)

edit: product tds is still zero