I'm not really sure what I have for an ro on this one. I changed it about a year ago. The replacement I just bought to run the second unit is a 90g with 99 percent rejection rate.
Help with RO/DI
- Thread starter -Logzor
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What are tap TDS and RO only TDS? What is the exact measured waste ratio? What is water temperature? What DI resin, is it fresh and if it's bulk how was it stored?
@AZDesertRat
Tap water tds is 93 today.
Tap on is about 6. I had to use my pool test stripes as I don't test pH in my tanks. So that may not be accurate.
Tap alk is 2.3 dkh via red sea
Ro only tds is 1
Tap temp is 57
Di resin is aqua fx mixed bed color indicating. Off the lfs shelf. Can't be too awful old since the store is only 9 months old.
One problem I found is the rejection rate is not high enough. I get 50ml of waste water for 35ml of good water.
This is a 60gpd unit. It was putting out 75 bad 25 good a few years ago when I set it up. I guess I never checked that when I change the ro last time. Assumed the same rated ro would do the same thing.
Go the the Spectrapure webpage, scroll down to the bottom left and open the FAQ section. Scroll down to the CO2 question and print the Nomograph they provide to calculate your CO2 content using the pH and alkalinity numbers.
No telling how old the DI resin is unless the bag is dated but under perfect conditions DI resin lasts about 6 months unopened. Perfect conditions means packed in vacuum sealed mylar foil bags, unopened, and stored in the refrigerator so it stays moist, cool and out of bright lighting. Once opened, unless you use it all, seal it back up with a Seal A Meal type vacuum food sealer and stick it in the fridge, it should last another 3-4 months if well sealed.
You are confusing rejection rate(removal efficiency) with waste ratio. The rejection rate is calculated using your tap TDS and RO only TDS, in your case 93 and 1. 93-1=92, 92/93=98.9, 98.9x100= 98.9% rejection rate. Waste ratio is the 50mL/35mL or 1.42:1 waste ratio which you are correct is too little waste. You have low TDS but you still want to try and get that between 2:1 and 3:1 using an untrimmed capillary tube flow restrictor you trim and adjust yourself to fit your exact conditions. They are $5-$6 at Spectrapure and Buckeye Hydro and you should always replace the flow restrictor with a new membrane as they go bad or plug up too.
No telling how old the DI resin is unless the bag is dated but under perfect conditions DI resin lasts about 6 months unopened. Perfect conditions means packed in vacuum sealed mylar foil bags, unopened, and stored in the refrigerator so it stays moist, cool and out of bright lighting. Once opened, unless you use it all, seal it back up with a Seal A Meal type vacuum food sealer and stick it in the fridge, it should last another 3-4 months if well sealed.
You are confusing rejection rate(removal efficiency) with waste ratio. The rejection rate is calculated using your tap TDS and RO only TDS, in your case 93 and 1. 93-1=92, 92/93=98.9, 98.9x100= 98.9% rejection rate. Waste ratio is the 50mL/35mL or 1.42:1 waste ratio which you are correct is too little waste. You have low TDS but you still want to try and get that between 2:1 and 3:1 using an untrimmed capillary tube flow restrictor you trim and adjust yourself to fit your exact conditions. They are $5-$6 at Spectrapure and Buckeye Hydro and you should always replace the flow restrictor with a new membrane as they go bad or plug up too.
Thanks. Yeah i could not think of the lingo for waste ratio but i knew you'd know what i meant. According to the calculator on the link from the specttrapures site, it says my co2 is 69 ppm.
https://www.hamzasreef.com/Contents/Calculators/CO2DIDepletion.php
About 70% of your DI life is being eaten up by the CO2 if your numbers are accurate. Sounds like building a simple degassing tower may be in your future. Your problem is your RO membrane and maybe only partially your DI resin but mostly CO2 in the water.
About 70% of your DI life is being eaten up by the CO2 if your numbers are accurate. Sounds like building a simple degassing tower may be in your future. Your problem is your RO membrane and maybe only partially your DI resin but mostly CO2 in the water.
hejjo
Well-Known Member
Hi sorry to go off topic a bit but I figured I would get the right answer here.
Is there a way to test a booster pumps transformer? My booster pump quit working and I'm not sure if it's the booster or the transformer. Thanks!
Btw The booster pump turns on but doesn't create pressure.
Is there a way to test a booster pumps transformer? My booster pump quit working and I'm not sure if it's the booster or the transformer. Thanks!
Btw The booster pump turns on but doesn't create pressure.
A voltmeter should show 24v DC if the power supply is good.
I would go to the pump manufacturers website and look for the owners manual or a troubleshooting guide. It's possible the pump could be plugged with calcium, particulates or even silt or sand if it is not protected by a filter.
I would go to the pump manufacturers website and look for the owners manual or a troubleshooting guide. It's possible the pump could be plugged with calcium, particulates or even silt or sand if it is not protected by a filter.
Fun fact to know and tell: In this hobby people like to think about the RATIO of "waste" water to purified water. This is the 4:1 you often hear of. 4 parts waste water to every 1 part of purified water produced.
A different way to think about this, and one that is really "more correct" is the RECOVERY. Meaning what percentage of the FEEDWATER is recovered as permeate (purified water).
If you have a 4:1 ratio, you have 1 part permeate for every 5 parts fed to the system, so you have a 1/5=20% recovery.
Russ
A different way to think about this, and one that is really "more correct" is the RECOVERY. Meaning what percentage of the FEEDWATER is recovered as permeate (purified water).
If you have a 4:1 ratio, you have 1 part permeate for every 5 parts fed to the system, so you have a 1/5=20% recovery.
Russ
WhiskeyCoffee
Well-Known Member
Wait a minute... Membranes have to stay flushed? Doesn't that contradict what you said here in 2010? @AZDesertRat
