Please help me select an RO/DI system!

[Potatohead]

That is not accurate, I have never heard of line pressure from city water above 50 PSI, My line pressure is 40, I do have a booster pump (and clearly stated in the directions were to never run the pump above 60 psi as it will cause damage to the membrane) There is a nominal performance difference with the pump on relater to gallons of water produced, however, I don't measure the amount of waste water I generate so I cant comment there. Also my water is zero or one TDS with or with out the pump.

?

My city pressure is over 68 psi, I have it reduced to that pressure where it comes in the house. You most definitely have less waste water the more pressure you run through the membrane.

 

[Doclight]

I Just got mine in last week. City water is at 65psi.. Directions in my kit state the it should be at least 60psi any less needs a pump... No problems with my water output.. I'm getting 0 tds...

Perhaps they changed something

 

[Holdbar7]

I have the BRS 5 stage but the 150g/day setup. It has been awesome! I recently bought another DI reactor though because silicate levels in my area are the biggest contam.

 

[Potatohead]

I Just got mine in last week. City water is at 65psi.. Directions in my kit state the it should be at least 60psi any less needs a pump... No problems with my water output.. I'm getting 0 tds...

Perhaps they changed something

TDS after DI doesn't tell the whole story, you need to measure your TDS out of the tap and then again after the membrane but before the DI. If you have higher pressure through the membrane and go from say 6 TDS after membrane down to 3 TDS, you have literally doubled your DI resin lifespan.

 

[Doclight]

TDS after DI doesn't tell the whole story, you need to measure your TDS out of the tap and then again after the membrane but before the DI. If you have higher pressure through the membrane and go from say 6 TDS after membrane down to 3 TDS, you have literally doubled your DI resin lifespan.

TDS at the tap is 440ppm ... After the RO part is 17ppm and at the DI resin its 0...

Our city water isn't great.. Imagine 440ppm going into your reef tank!

 

[Potatohead]

So you are getting about 96% rejection is not bad. If you had a booster pump running at say 85 psi you and bumped to 98% rejection, your TDS is now 9 out of the membrane and your DI life would double. You also would have less waste water. People never want to buy booster pumps but there really is no downside, depending how much water you are making it will pay for itself many times over in longer resin life.

 

[Doclight]

I don't disagree.. I'll be ordering a booster soon.. Just needed other goodies to begin with.. But the comment was about the post on "no city has above 50psi" water pressure.. At 50psi you GOT to have one.

Back to OP post.. I'd go 150.. just because you get the dual di resin, and that means you have to change it less, you get the dual tds meter and the pressure gauge. All make a big difference.

One other thing.. No matter what you buy, get the tube conditioner for the o rings. Makes changing the di resin so much easier.

 

[Doclight]

https://www.bulkreefsupply.com/dow-111-o-ring-lubricant.html

 

[LagunaGlide]

So you are getting about 96% rejection is not bad. If you had a booster pump running at say 85 psi you and bumped to 98% rejection, your TDS is now 9 out of the membrane and your DI life would double. You also would have less waste water. People never want to buy booster pumps but there really is no downside, depending how much water you are making it will pay for itself many times over in longer resin life.

I don't disagree, but also new to the Ro/Di thing, so still getting an understanding of it. I am, and have been toying with the idea of getting a booster.

 

[jimmyzhou]

Everyone psi won’t be the same came form inline. If I don’t have booster pump. My inline only 35 psi

 

[Canan]

I would recommend the below action plan before giving any decision;

1. Check the TDS of your city water
2. Depending on the TDS level, you can decide for the stages of the RODI system (the TDS at my home is 5 ppm, 3 stage +RO is sufficient for my application.)
3. If your TDS is high -say more than 100 ppm- before deciding for a 5 or 6 stage RODI, having a finer sediment/VOC filter (1 micron or less) will reduce the load on your DI resin and you may still go with a 4 stage RODI system.
4. If your TDS is quite high (more than 300ppm), I would strongly recommend and an inline/continuous filtration on your main incoming water (sediment/carbon filters along with water softener). This will definitely support your RODI selection, more than this, you will reduce the risk of some other health and equipment problems you may face at home.

A typical RODI water system will waste 3 gallons of water to produce 1 gallon of quality water (you can use this to calculate your efficiency). However, if the input TDS is too high, you will need more stages to achieve the result which will increase the waster water amount (each stage may add 1 gallon of extra waste). You can use this thumb rule to calculate the efficiency.

I would also recommend keeping 1 set of spare filters and resin kit available at home along with some repair kits.

 

[Opus]

The sediment and carbon filters have no effect on tds so will not reduce the load on the DI. They are only there to protect the RO membrane. My tap water is around 450 tds and I get 5 tds out of the membrane. I can go around 5 years on a RO membrane.

OP, what ever you decide, make sure to get the kit that allows you to switch the water coming out of the RO membrane to the waste line and bypass the DI filter so you can get rid of tds creep before switching it back over to the DI filter.

 

[Forsaken77]

Hello,


I have narrowed my search down to two contenders for an RO/DI system for my home. They are the BRS 75gpd Plus 5 stage RO/DI system and the AquaFx 100gpd Platinum Barracuda RO/DI system. Which would you suggest and why?


I have a whole house water softener system installed as well, a RainSoft EC5 that will be filtering all my water before it even hits the RO/DI system.


All input is appreciated. Thanks in advance!

Edit: Forgot to mention this is to help maintain my Red Sea Max 250 reef tank. I live quite far from the LFS, so this is really a necessity at this point.

I wouldn't pick either. While that is a smaller tank, and you could get away with the 75gpd setup, I personally would go with at least a 100gpd system. I wouldn't overpay for the Aqua FX one either. 75 gpd just takes too long imo.

I would buy the cheap 4 Stage 100 gpd Marine Depot System, then add the BRS Universal to Universal Plus Upgrade Kit (with the glycerin filled pressure gauge, triple inline tds meter, and the 100 gpd flow restrictor). You would have to call BRS when making the Upgrade kit order because they only include the 75 gpd restrictor and you'd need the 100.

I would also HIGHLY recommend the Auto Shut Off Kit from BRS. It has to be drilled into your reservoir for the float switch (it's very easy with detailed YouTube videos), but will prevent floods if you forget to turn it off... And we all do at one point.

Most systems use the capillary flow restrictors inside the tubing, but the BRS Restrictor, that comes in the kit, is a restrictor & flush valve in one. You would need the 600Ml for a 100 gpd system (it's cheaper than the 75 gpd restrictor). You also should put a 3-Way Ball Valve after the membrane, before the DI resin, so you can flush the membrane without it going through the DI resin.

Then the best filters are the 100 gpd DOW Membrane, GE 1 Micron RO Save.Z Depth Sediment Filter, and the Spectrapure High Capacity Color Changing Silicabuster DI Resin. You can easily use the filters and membrane that come with the unit, these are just better replacements for when they have to be changed.

I personally built my own out of all the components, but this setup is my suggestion. All links to the equipment are there for you to check out.

 

[Whipples]

You also would have less waste water

This is only part of the story. The decrease in waste water you are seeing is due to the flow restrictor now not being tuned to the PSI you are pushing through the membrane as most are tuned out of the box for a certain PSI rating which we don't all have and also aren't necessarily running 77F temperature source water into the membranes either. Less waste water is not always a great thing, and it is not really "waste" as much as it is "flush" water, or brine. Unless you have really soft water, or water with less than 150-200 TDS, you should really not aim for a ratio less than 3:1 as you will foul the membrane faster, have increased TDS creep upon startup which eats DI resin faster, and generally more likely to run into problems down the road. I wouldn't even consider a second membrane with source water TDS>200 as now you are pushing the brine, or flush water, from one membrane which now has even more TDS (because it was rejected by the first membrane) into a second membrane. If your flush to product water is less than 3:1, your flow restrictor on the flush water/brine output of the membrane needs to be adjusted. If you have TDS>300, 4:1 will provide better life to the membrane, performance, and is industry standard for a reason.

I 100% agree with you on booster pumps and run one myself to get 90 PSI to the membrane, which gives me 99% rejection rate measured via pre and post-membrane samples. I run my brine water into my top-loading washing machine and try to make water on laundry days in order to better utilize the water I am paying for.

Remember to change out carbon/sediment filters on a regular basis to maintain the membrane and performance of the unit, I do mine every 6 months as the cost of carbon/sediment filters is cheap and here in SoCal our water is a bit harder than others.

EDIT: be careful running >70PSI on some units, if you do make sure you observe fittings for leaks, cracks, etc. Not all RODI canisters are made equal!

 

[chris k.]

Check your city water for chlorine or chloramine. If it is chloramine or will need a different carbon block for that.

 

[Potatohead]

This is only part of the story. The decrease in waste water you are seeing is due to the flow restrictor now not being tuned to the PSI you are pushing through the membrane as most are tuned out of the box for a certain PSI rating which we don't all have and also aren't necessarily running 77F temperature source water into the membranes either. Less waste water is not always a great thing, and it is not really "waste" as much as it is "flush" water, or brine. Unless you have really soft water, or water with less than 150-200 TDS, you should really not aim for a ratio less than 3:1 as you will foul the membrane faster, have increased TDS creep upon startup which eats DI resin faster, and generally more likely to run into problems down the road. I wouldn't even consider a second membrane with source water TDS>200 as now you are pushing the brine, or flush water, from one membrane which now has even more TDS (because it was rejected by the first membrane) into a second membrane. If your flush to product water is less than 3:1, your flow restrictor on the flush water/brine output of the membrane needs to be adjusted. If you have TDS>300, 4:1 will provide better life to the membrane, performance, and is industry standard for a reason.

I 100% agree with you on booster pumps and run one myself to get 90 PSI to the membrane, which gives me 99% rejection rate measured via pre and post-membrane samples. I run my brine water into my top-loading washing machine and try to make water on laundry days in order to better utilize the water I am paying for.

Remember to change out carbon/sediment filters on a regular basis to maintain the membrane and performance of the unit, I do mine every 6 months as the cost of carbon/sediment filters is cheap and here in SoCal our water is a bit harder than others.

EDIT: be careful running >70PSI on some units, if you do make sure you observe fittings for leaks, cracks, etc. Not all RODI canisters are made equal!

To be clear I don't think people should be running less than 3:1 waste either, but I know on my system an increase from 50 to 66 psi brought my waste from 4.2:1 down to 3.7:1. So, it's a sizeable difference without being detrimental. It is possible if I ran my system at 85-90 psi it could drop too far. A flush valve between the DI and membrane is also important, agree there too.

Now to be honest despite what I said earlier I don't use a booster pump because I use up my waste water doing water changes on my 200g Frontosa tank, and the TDS out of my tap is only 14 (lol). If not for those things I definitely would and for most people not in the same situation they make tons of sense.

 

[robert teseo]

I use the vertex rodi 100 gpd system with the booster pump and tds meter built in from marine depot. I,m very happy with it

 

[Whipples]

@Potatohead jealous of that source water! I get about 200 out the tap which is very good for San Diego, just a few miles up the road at our last place I would get 450!!

 

[Kengar]

I have a SpectraPure UHE 200 gpd unit (http://spectrapure.com/RO-RODI/RODI-SYSTEMS/MaxCap-1-1-Ultra-High-Efficiency-200-GPD-RO-DI-System) and LOVE it. Yes it's pricey, but I think it pays off in the end.

It is float-switch controlled to turn on automatically when RO storage bin gets low and turn off automatically when bin is full. In other words, it is supplied by a line from water supply that is always on, and a solenoid valve on the unit opens and closes to control flow through the unit. (I put a ball valve in the feed line to isolate the RO/DI unit as needed, e.g., when I change sediment or carbon-block pre-filter, which are upstream of the solenoid-controlled valve.)

While the unit is running, it will automatically rinse the membranes once an hour (I think) using product water by pulling water back out of the RO storage bin and running it through the unit. When the bin gets full and the unit is about to shut down, it runs another flush and then shuts down with the membranes soaking in RO water that has been pulled back through.

My source water is coming in at a TDS reading of about 300, and water comes "off the membrane) at 4. After well over 2 years of usage (albeit only to supply makeup and water changes for a 15, since the 250 build I bought this for went sideways due to need to fix point of sale workmanship on tank from Coast to Coast Aquariums (search for me on the board, you'll see what I'm talking about.......)), I have just now first needed to change out the MaxCap cartridge. Given reduced wastewater, longer period of time between DI cartridge changes, and automatic on/off function, I am absolutely delighted by the unit.

If you call them to order, tell them Ken Fagin recommended it.

 

[Whipples]

I use Spectrapure everything except for booster pump because they don't make one, cannot recommend them enough!