Best RODI for the $$$$

[monkeyCmonkeyDo]

Air water and ice. Call em. They will get you a rodi unit within your $ needs and will work for what you need. You need a smaller unit for under the sink? They will help you.
The stages depends on your starting tds from the tap. I recommend a 4-6 stage unit if your will be doing mixed reefs.
D

 

[zalick]

I have a 90 gpd spectipure

move had it for years . Chance filters , resin and that’s it for maintenance .

when I got it . There was supposedly a way to calibrate the ratio of waste to good water
But said it was 3:1 ?
I honestly haven’t measured

You can put a valve on the waste line to calibrate. No need to fiddle with the flow restrictor tube length (DIY hack that Spectrapure tech support told me)

 

[monkeyCmonkeyDo]

I would not restrict the output flow of my rodi unit. All you would do is foul your ro membrane sooner. Imo.
D

 

[zalick]

I would not restrict the output flow of my rodi unit. All you would do is foul your ro membrane sooner. Imo.
D

Depends on your membrane quality and local water supply. Most units have a flow restrictor that you insert to get the proper waste ratio. Maybe all do but I haven't seen all units. If you didn't have a flow restrictor, and instead just had the waste line be 1/4 tube, your waste ratio would be insanely high and you wouldn't make any water since the water takes the path of least resistance (your unrestricted waste line).

My membrane is rated for 2:1 but my tap water supply is very low TDS (~30) so I have it tuned to 1:1. I've processed maybe 15,000 gallons on my current membrane and only burned through 1 DI cartridge.

 

[monkeyCmonkeyDo]

Yes most rodi produce probably double the waste water vs 0 tds rodi. My unit has a flush valve.for the ro.membrane..i can.turn the water on or off though the membrane. The water.free.flows through my pre stages and the final di stage.
D

 

[monkeyCmonkeyDo]

You are increasing the pressure inside the unit with back pressure. U want a booster pump to boost the pressure going through the unit.
D

 

[monkeyCmonkeyDo]

This will increase your rodi to waste ratio.

 

[KStatefan]

My membrane is rated for 2:1

What membrane are you using? What is the rejection rate at 2:1?

 

[zalick]

What membrane are you using? What is the rejection rate at 2:1?

I have a maxcap 180 that uses two spectraselect plus 90gpd membranes. I also have a booster pump set to 80psi. My rejection rate is 100% at 1:1 as far as I can tell. It's always 30-50 TDS in and 0 TDS out. Just checked and I've processed 16,200 gallons through these membranes. I installed a water meter on the input line to track usage.

 

[KStatefan]

I have a maxcap 180 that uses two spectraselect plus 90gpd membranes. I also have a booster pump set to 80psi. My rejection rate is 100% at 1:1 as far as I can tell. It's always 30-50 TDS in and 0 TDS out. Just checked and I've processed 16,200 gallons through these membranes. I installed a water meter on the input line to track usage.

I use the same membrane but just one since my source water is 400+ TDS I wish my source water was as good as yours. You are able to run with much less waste water. The membrane is rated at 15% recovery.

 

[zalick]

I use the same membrane but just one since my source water is 400+ TDS I wish my source water was as good as yours. You are able to run with much less waste water. The membrane is rated at 15% recovery.

My water is great except for the chloramine. I have to run a big blue carbon block instead of a regular carbon. But it also lasts much longer $ for $ than the regular or even chloramine blocks. I was burning through those regular blocks rapidly. Chloramine sucks.

 

[missourimud]

since this thread is old but has lost it purpose anyway maybe you guys could help me?
i have a brs 150 gpd water saver (2 ro membranes) works great but i have ran maybe 50-60 gallons through it and my DI resin has already changed colors to the top! I start using it with the flush open- run for 2-3 minutes while getting set up, run my jug usually 5 gal at a time. then i turn flush back on for about 5 minutes afterward. is this the correct process? while running today i saw that i had 1 tds output for maybe 2 gallons before it dropped to 0. seems like my DI exhausted quick.
my source water is 337 tds but i do run into a water softener once it reaches the house. If i am doing something wrong let me know. i can run in larger batches i just didnt want it sitting around
thanks

 

[Casper12065]

since this thread is old but has lost it purpose anyway maybe you guys could help me?
i have a brs 150 gpd water saver (2 ro membranes) works great but i have ran maybe 50-60 gallons through it and my DI resin has already changed colors to the top! I start using it with the flush open- run for 2-3 minutes while getting set up, run my jug usually 5 gal at a time. then i turn flush back on for about 5 minutes afterward. is this the correct process? while running today i saw that i had 1 tds output for maybe 2 gallons before it dropped to 0. seems like my DI exhausted quick.
my source water is 337 tds but i do run into a water softener once it reaches the house. If i am doing something wrong let me know. i can run in larger batches i just didnt want it sitting around
thanks

Sounds like you are running the flush valve correctly based on everything I've heard. You may just have a lot of TDS in your water, making it past the previous filters, and eating up your resin quicker. Can you add another carbon block or maybe change out the existing carbon and sediment filters if they have been in use a long time? Does your RO/DI system have a tds meter that measures TDS before it gets to the resin? That would be a clear indicator of whether a lot of TDS is making it to the resin stage of the filter and wasting it. If your tap water is treated with chloramine instead of chlorine that can rip through the resin too.

 

[zalick]

since this thread is old but has lost it purpose anyway maybe you guys could help me?
i have a brs 150 gpd water saver (2 ro membranes) works great but i have ran maybe 50-60 gallons through it and my DI resin has already changed colors to the top! I start using it with the flush open- run for 2-3 minutes while getting set up, run my jug usually 5 gal at a time. then i turn flush back on for about 5 minutes afterward. is this the correct process? while running today i saw that i had 1 tds output for maybe 2 gallons before it dropped to 0. seems like my DI exhausted quick.
my source water is 337 tds but i do run into a water softener once it reaches the house. If i am doing something wrong let me know. i can run in larger batches i just didnt want it sitting around
thanks

Something is wrong. You should message BRS. No way your DI should exhaust that quickly with TDS 0 after your RO.

 

[KStatefan]

since this thread is old but has lost it purpose anyway maybe you guys could help me?
i have a brs 150 gpd water saver (2 ro membranes) works great but i have ran maybe 50-60 gallons through it and my DI resin has already changed colors to the top! I start using it with the flush open- run for 2-3 minutes while getting set up, run my jug usually 5 gal at a time. then i turn flush back on for about 5 minutes afterward. is this the correct process? while running today i saw that i had 1 tds output for maybe 2 gallons before it dropped to 0. seems like my DI exhausted quick.
my source water is 337 tds but i do run into a water softener once it reaches the house. If i am doing something wrong let me know. i can run in larger batches i just didnt want it sitting around
thanks

I would recommend to add a DI bypass valve to dump the TDS creep down the drain prior to getting to the DI resin. What is the rejection rate of your membrane?

 

[missourimud]

so my rejection rate is 2:1. it has, according to my knowledge 2 RO membranes being the water saver model. it is not a old unit, no more than 2 months and 60 gallons top. it has the tds meters on input and output side of the DI cannister. when i run it i turn the flush valve on but it does feed some through the di resin, it will spike as high as 80 tds before working back down to low single digits. i could tee off of this line to allow that water to stay out of the DI if that would be advisable? i dont know whats coming into the entire unit as it has already passed my water softener but i will post the city reports if you have any guidance let me know- thanks

 

[KStatefan]

@missourimud A DI bypass valve is what you are describing and that is how you remove TDS creep so it does not get to your resin. I added an automatic bypass valve on my system so when the signal to make more RODI comes on the first couple minutes of produce is sent down the drain.

From your water your report your incoming water is 341 TDS your soften water will be about the same.