RODI Filter Upgrade to Help

[kboogie]

I have a BRS 6 Stage 75GPD RODI filter. I need to replace the media and membrane. I also want to increase the flow by adding a second membrane and booster pump. . I have a dual DI setup.

I am a huge Amazon buyer because of their easy and free next day shipping as a prime member. With that said I’m looking for assistance in finding the following:

1. A second membrane unit with Y adaptor to unify the product output of both membranes.
2. DI Resin, Carbon Block, and Particulate filter recommendations. I want carbon specialized for chloramine removal. I have relatively particulate free water.
3. What is the best/highest flow membranes and what size booster pump would I need based on the membranes. Can I get two 200GPD membranes and get to 400GOD (both items listed below)?

https://a.co/d/0cMZ6GZh

https://a.co/d/074OfUnu

 

[kboogie]

Here is the report from my Water Treatment Plant. When I test water at my tap, it is between 160 and 180ppm TDS, which aligns with what the report suggests.

 

[kboogie]

I'm looking at these carbon blocks:

1 Micron Heavy Metal Removal Carbon Filter
They remove the normal stuff plus add heavy metal removal.

I am thinking about this kit to add a second membrane. It comes with a 150 which I think will be useful if I find the pressure going into the second membrane is not high enough to support the 200 GPD.

Water Saver 150 GPD Membrane Holder Kit

I'm thinking about these resin beads

Awesome Aquatic Mixed Bed DI Resin MDB-30

I'm also thinking about this sediment filter:

PurePlus 5-Micro Sediment Filter

 

[UncommonSense]

I’d personally recommend going through BRS or Buckeye hydro for these parts for several reasons:

— Not all water filtration products are created equal…

— I keep hearing, and have personally seen amazon sellers become increasingly predatory/borderline scammy… (blatantly false product descriptions, charging 50% restock fee and shipping both ways for returns, shipping products multiple months after date of purchase, etc…)


This said, there’s a lot to this subject…

— RO membranes: Dow Filmtec 75GPD RO membranes are the reefing gold standard for a good reason, they are pretty much the only universal membrane on the market that can reliably perform at 99% TDS rejection rate…

— Sediment filters and carbon blocks likewise can be made with numerous grades of quality… I usually get GE’s ROsave.Z sediment filters (graded from 1micron to .1micron to trap more sediment)

— I usually use BRS universal carbon blocks; their recipe doesn’t seem to have changed over the years, and they definitely weigh more than many competitors (more carbon)… they do also sell chloramine specific carbon blocks!

— You want the product water coming out of your RO membrane(s) to be as low in PPM TDS as possible… (4ppm water exhausts DI resin 2x faster than 2ppm water!)

— you will likely need to switch flow restrictor size for this application to avoid membrane damage

— you’ll likely want a pre-RO membrane pressure gauge for this application, primarily for diagnostics and booster pump tuning

— booster pumps also are not all created equal… the Aquatec 8800, or the ROBuddy 150gpd are the two most well documented and known reliable options… I use the former!


—75GPD dow membranes are rated for that flow, and 99% TDS rejection at ~60PSI… the performance only increases as pressure increases! You can easily get over 100gpd of product water per-membrane at max operating pressure of 85PSI!


I’m just leaving bullet points here, this is a relatively complex topic, of which I’m just scratching the surface…

@Buckeye Hydro , would you mind jumping in here to add your expert advice for this upgrade?

 

[kboogie]

I’d personally recommend going through BRS or Buckeye hydro for these parts for several reasons:

— Not all water filtration products are created equal…

— I keep hearing, and have personally seen amazon sellers become increasingly predatory/borderline scammy… (blatantly false product descriptions, charging 50% restock fee and shipping both ways for returns, shipping products multiple months after date of purchase, etc…)


This said, there’s a lot to this subject…

— RO membranes: Dow Filmtec 75GPD RO membranes are the reefing gold standard for a good reason, they are pretty much the only universal membrane on the market that can reliably perform at 99% TDS rejection rate…

— Sediment filters and carbon blocks likewise can be made with numerous grades of quality… I usually get GE’s ROsave.Z sediment filters (graded from 1micron to .1micron to trap more sediment)

— I usually use BRS universal carbon blocks; their recipe doesn’t seem to have changed over the years, and they definitely weigh more than many competitors (more carbon)… they do also sell chloramine specific carbon blocks!

— You want the product water coming out of your RO membrane(s) to be as low in PPM TDS as possible… (4ppm water exhausts DI resin 2x faster than 2ppm water!)

— you will likely need to switch flow restrictor size for this application to avoid membrane damage

— you’ll likely want a pre-RO membrane pressure gauge for this application, primarily for diagnostics and booster pump tuning

— booster pumps also are not all created equal… the Aquatec 8800, or the ROBuddy 150gpd are the two most well documented and known reliable options… I use the former!


—75GPD dow membranes are rated for that flow, and 99% TDS rejection at ~60PSI… the performance only increases as pressure increases! You can easily get over 100gpd of product water per-membrane at max operating pressure of 85PSI!


I’m just leaving bullet points here, this is a relatively complex topic, of which I’m just scratching the surface…

@Buckeye Hydro , would you mind jumping in here to add your expert advice for this upgrade?

Thank you for the feedback. The carbon block and the DI Resign are the two items about which I'm most concerned when purchasing from Amazon. I agree that the BRS items are curated. I was wondering if people have found either the identical products for cheaper or really good alternatives.

Regarding the booster pump, I plan on buying the Aquatic Life Smart Buddie system.

It is my understanding that one of the items that reduces the efficiency of the higher flow membranes is pressure, and the booster pump will improve the efficiency. While 99% purirty out of the membrane reduces the rate at which the DI resin is consumed. In my 75 GPD system, my TDS going into my resin should be around 1 to 3 TDS if that needs to double in order for me to get 4x to 6x flow, I'm OK with that.

 

[UncommonSense]

In my 75 GPD system, my TDS going into my resin should be around 1 to 3 TDS if that needs to double in order for me to get 4x to 6x flow, I'm OK with that.

How much DI water are you making per-batch?

There are several ways to “speed” the process up without resorting to burning through DI resin rapidly! — for example, a larger accumulator tank, or a float valve in a water tank!

 

[kboogie]

How much DI water are you making per-batch?

There are several ways to “speed” the process up without resorting to burning through DI resin rapidly! — for example, a larger accumulator tank, or a float valve in a water tank!

I have three use cases for RODI. They are as follows:

1. Water changes for my three aquariums, depending on the aquariums, I make between 40G and 130G per water change. It can take 2.5 days to make the water, and it ends up sitting for a week before I have the spare time to do the water change because I lose my weekend window. During the 2.5 days, I have the tube/hose dragged from my laundry room, where the filter is located, to my home office. The hose stretches across a high traffic area (access to the garage where my wife and I park our cars and the vanity bathroom, which is the most used bathroom downstairs).

2. ATO refill, I have a 24-gallon ATO reservoir for my 300G FOWLR, which needs to be refilled every week and takes about 7 hours, and it has the aforementioned problem with the high-traffic area.

3. Manual topoff for my two QT tanks, one located in the en suite bathroom of the guest bedroom, and the other located in the foyer. This occurs multiple times a week.

Unfortunately, I don't have any space for a big storage tank, and the cost of those tanks is obscene. The long fill times have resulted in numerous floods and other issues related to waiting. I've had no success with float switches. I am expecting the Smart Buddie's pressure-based shutoff to help with the float switch issue.

It is important to note that my current DI resign lasts three years plus, so if I have to change the resin yearly, that is a huge win to dramatically reduce the impact of the files.

If my math is correct, even the 200 GPD membrane operates at 97%, which is below what I should achieve with a booster, that means my 130 TDS input would be 3 TDS going into the DI resin. Right now, I'm at 1 to 2 TDS with the 75 GPD membrane and no booster. I do wonder what the TDS coming out of the second membrane would be.

 

[UncommonSense]

I have three use cases for RODI. They are as follows:

Oof! Yeah, you need an upgrade!

— is the likes of a 1/4”-3/8” RO line run through the wall/attic out of the question? This would let you bypass the high traffic areas, and avoid messing with long lengths of tubing every week or two!

Unfortunately, I don't have any space for a big storage tank, and the cost of those tanks is obscene.

Agreed, the cost of some tanks is crazy! I was thinking of the usual 55g brute can with a float valve in it!

I've had no success with float switches. I am expecting the Smart Buddie's pressure-based shutoff to help with the float switch issue.

The float switches definitely do suck!

I’m referring to a mechanical valve with a float controlling when it opens/closes! These are not foolproof, but they tend to be quite reliable when used strictly to turn an RODI system on/off by opening/closing in the desired fill container!

It is important to note that my current DI resign lasts three years plus, so if I have to change the resin yearly, that is a huge win to dramatically reduce the impact of the files.

Wow! On standard 10”x2.5” cartridges of resin? Incredible!

In that case, you could get away with a higher DI resin input TDS!

— I’m just not sure exactly how fast you can push RO water through standard DI resin cartridges while still getting 0 TDS reliably!

130 TDS input would be 3 TDS going into the DI resin. Right now, I'm at 1 to 2 TDS with the 75 GPD membrane and no booster

yeah, 3-4ppm, depending on how much rejection gain the booster pump gets you! (I also wonder about the smart buddy maxing out on flow here, though… the largest model is only rated for 150gpd… and, they have a built-in flow restrictor which likely isn’t compatible with dual 200gpd membranes… i think Aquatec might make a 3/8” fitting size booster pump that would work at this flow rate..,)

I do wonder what the TDS coming out of the second membrane would be.

Despite the “water saver” claim, the waste water rejection rate is exclusively predicated by the waste line flow restrictor… adding an extra membrane without changing the waste line restrictor will increase your product water volume without increasing your waste water volume, but can increase RO product TDS and/or scale the membranes as a consequence…

Because the waste line of RO membrane #1 is the water supply line for RO membrane #2, there is an expectation that these membranes run in series… however this is not the case; they run in parallel!

— membrane housing #1’s water supply line input is a direct shot to membrane housing #1’s waste water output! — the only thing stopping supply water from just ignoring the RO membrane completely and shooting out the waste line is the aforementioned waste line flow restrictor!

— so, by supplying membrane housing #2 with the “waste” water outlet of membrane housing #1, and moving your waste line flow restrictor to the waste outlet of membrane housing #2, you’ve got both membrane housings pressurized with the same TDS supply water, bleeding high TDS waste through the waste line flow restrictor!

(All this is to say you’ll need a relatively high flowing waste line flow restrictor for dual 200gpd membranes, plus booster pump!)

 

[Shirak]

A lot going on here! As mentioned flow restrictor would need to be changed and sized correctly if you add a second membrane or just change the one membrane to a higher output. Also keep in mind the booster pump needs to be large enough to supply enough flow and pressure for your desired output.

 

[kboogie]

Oof! Yeah, you need an upgrade!

— is the likes of a 1/4”-3/8” RO line run through the wall/attic out of the question? This would let you bypass the high traffic areas, and avoid messing with long lengths of tubing every week or two!

Funny you should ask. I looked into running through the space used by the HVAC vents. Since it would be the first floor of a two-story house, the space is tight. The biggest issue is that there is a firewall that is not accessible wihtout cut a large chunk out of the ceiling. The HVAC people told they ducts are installed before the ceiling, so they have access when the house is being built. I also looked into pulling the crown molding, but I wouldn't be able to go up and over the door for the vanity bathroom next to my home office. I had an AC drainline leak that damage the wall in the hallway. My contractor looked in the wall when he opened it up because I figured I might as well take advantage of the situation, and he said he didn't have a way to get a line there from the inside. I would have to go from the outside. I really don't like having holes drilled on the outside. We had a really bad experience when I was a kid. I have very little luck with these things.

Agreed, the cost of some tanks is crazy! I was thinking of the usual 55g brute can with a float valve in it!



The float switches definitely do suck!

I’m referring to a mechanical valve with a float controlling when it opens/closes! These are not foolproof, but they tend to be quite reliable when used strictly to turn an RODI system on/off by opening/closing in the desired fill container!

I'm not familiar with this kind of float switch. I'll look into it.

Wow! On standard 10”x2.5” cartridges of resin? Incredible!

In that case, you could get away with a higher DI resin input TDS!

— I’m just not sure exactly how fast you can push RO water through standard DI resin cartridges while still getting 0 TDS reliably!

I was wondering the same thing. Few vendor make it easy to find the flow rate spec for their efficiency claims. I saw a coupe resins and carbon blocks with ranges as high as 3 gallons a minute and 1 gallon on the low end. I saw a cheap product that was 0.5 gallons per minute but I would buy that any way. I was pleasantly surprised by the amount of flow you could put through the cabon block and resin.

yeah, 3-4ppm, depending on how much rejection gain the booster pump gets you! (I also wonder about the smart buddy maxing out on flow here, though… the largest model is only rated for 150gpd… and, they have a built-in flow restrictor which likely isn’t compatible with dual 200gpd membranes… i think Aquatec might make a 3/8” fitting size booster pump that would work at this flow rate..,)

The good news is Aquatic Life makes a 200 GPD Smart Buddie. The SKU is 660730. It is available on Amazon for $157. The price difference between the 75 GPD Smart Buddie and 200 GPD Smart Buddie is so small ($15), I wonder why they don't make one unit with an adjustable flow rate.

Despite the “water saver” claim, the waste water rejection rate is exclusively predicated by the waste line flow restrictor… adding an extra membrane without changing the waste line restrictor will increase your product water volume without increasing your waste water volume, but can increase RO product TDS and/or scale the membranes as a consequence…

Because the waste line of RO membrane #1 is the water supply line for RO membrane #2, there is an expectation that these membranes run in series… however this is not the case; they run in parallel!

— membrane housing #1’s water supply line input is a direct shot to membrane housing #1’s waste water output! — the only thing stopping supply water from just ignoring the RO membrane completely and shooting out the waste line is the aforementioned waste line flow restrictor!

— so, by supplying membrane housing #2 with the “waste” water outlet of membrane housing #1, and moving your waste line flow restrictor to the waste outlet of membrane housing #2, you’ve got both membrane housings pressurized with the same TDS supply water, bleeding high TDS waste through the waste line flow restrictor!

That is so cool. I never would have thought it would end up being parallel. That's so good to know. I was concerned that high TDS wastewater would be going to the second membrane.

(All this is to say you’ll need a relatively high flowing waste line flow restrictor for dual 200gpd membranes, plus booster pump!)

I'm surprised the kits I've seen don't come with the new restrictor. Do you have any thoughts on the specs of the appropriate restrictor, or are they explicitly labeled for the membrane flow rate? EDIT: I found the answer to this question. They do label the restrictors in ML/Min. I would need 2,000 ML/Min restrictor.

BTW, thank you so much for the engagement. You have made me aware of many things I previously wasn't aware.

 

[kboogie]

@UncommonSense, I forgot to mention. Another fear I have is the high pressure from the booster pump my cause leaks or even break the membrane housing. I did see a full RO system that did mention the maximum pressure the system supported, but I haven't see anything for add-on housings or the BRS unit. I hope they don't mention this because they support much higher pressures than can be generated by the booster pump, but I figured I would ask.

 

[UncommonSense]

@UncommonSense, I forgot to mention. Another fear I have is the high pressure from the booster pump my cause leaks or even break the membrane housing. I did see a full RO system that did mention the maximum pressure the system supported, but I haven't see anything for add-on housings or the BRS unit. I hope they don't mention this because they support much higher pressures than can be generated by the booster pump, but I figured I would ask.

I’m using a 12-ish year old BRS 6-stage “water saver” RODI system with several modifications, and a Aquatec 8800 booster pump, for context…

While exceeding the factory rated 90PSI is not recommended, I have personally had success at 95PSI for 7-ish years, but am running 90PSI these days…

Other users have claimed running 110PSI with no issues for extended periods, and I’ve seen some users claim anything from 125+psi to pegging the gauge during extreme cases of bad installation…

All this to say that just because it is possible to run >90PSI pre-membrane line pressure, doesn’t mean you should do it! — tubing, fittings, and the housings themselves can rupture, and are only as strong as the weakest link! (Think, cheap fitting, old/hard o-ring, scuffed/deep scratched tubing… or even just age/manufacturing defect on reputable parts!)

— these booster pumps typically can, and will be able to over-pressurize your system once it’s sealed off! they are regulated by an automatic shutoff switch (usually triggering @40PSI on the RO product water tubing, this will be built into your RO buddy, and is another potential restriction point!)

— as an aside, my system, with two 75gpd Dow Filmtec membranes @95PSI made right around 240GPD @ 1-2ppm TDS… I’m starting to realize that you’ll probably need to replumb your system to 3/8” tubing/fittings, up to the RO membranes, too! (The prefilter housings are typically 1/4” NPT, > in inside diameter than 3/8” tubing, so no need for new housings…)

— this is starting to look like a job for a custom system, or dual systems teed into one 3/8” line to the tanks, and one 3/8” line to waste! (Specifically, you’ll be moving around 1,800gpd for 1:2 product:waste ratio, or 3,000gpd for a 1:4 product:waste ratio… 1.25-2 gallons per minute!!)

 

[UncommonSense]

I would have to go from the outside. I really don't like having holes drilled on the outside. We had a really bad experience when I was a kid. I have very little luck with these things.

Hmm… I can understand those sentiments!

Just as food for thought; you can pass through an exterior wall via an electrical box, with waterproof exterior cover plate!

Alternatively… do you have a crawlspace under the first floor? Or are you on a concrete slab?

I'm not familiar with this kind of float switch. I'll look into it.

BRS sells some good ones, or at least they did when I got my RODI! I’m still using the one that came with my system, and it still works like-new/holds city water pressure no problem!

— in fact, this is how your toilet’s water tower knows when to stop filling, or even many large, multi thousand gallon water tanks!

— they have gotten a bad rap over time due to their prevalence for ATO systems years ago… they can get stuck in the “on” position if a snail/etc crawls into the mechanism while they are filling! (Hence why I specify that they have proven to be reliable for water making containers!)

The good news is Aquatic Life makes a 200 GPD Smart Buddie. The SKU is 660730. It is available on Amazon for $157. The price difference between the 75 GPD Smart Buddie and 200 GPD Smart Buddie is so small ($15), I wonder why they don't make one unit with an adjustable flow rate.

I’m wondering if you’d need to run two of these in parallel to get dual 200GPD membranes to flow at full output… the sheer water volume desired calls for some abnormal design considerations, primarily revolving around flow restrictions within various parts, fittings, and tubing…

BTW, thank you so much for the engagement. You have made me aware of many things I previously wasn't aware.

Happy to help! The whole subject of RODI systems is something of a black magic until you really start wrapping your head around all the operating principles and plumbing layouts… then, it all starts to click and make a lot of sense!

 

[19Mateo83]

Just gonna drop this option in here…. I purchased one of these and it has been a great little unit. Makes a gallon in about 5 minutes @80psi. Is rated for 150 psi so room to boost it if needed and has 1.5:1 rejection rate. Dow filmtec membrane. Free shipping too.

IceCap 200gpd RO/DI System (OPEN BOX)

BRAND NEW, OPEN BOX

store.coralvue.com

 

[Buckeye Hydro]

I'm not keen on jumping into a thread to try to sell Buckeye Hydro products when people seem already convinced to buy elsewhere. If you have a specific question we'll try to address it.

Russ

 

[kboogie]

I’m using a 12-ish year old BRS 6-stage “water saver” RODI system with several modifications, and a Aquatec 8800 booster pump, for context…

While exceeding the factory rated 90PSI is not recommended, I have personally had success at 95PSI for 7-ish years, but am running 90PSI these days…

Other users have claimed running 110PSI with no issues for extended periods, and I’ve seen some users claim anything from 125+psi to pegging the gauge during extreme cases of bad installation…

All this to say that just because it is possible to run >90PSI pre-membrane line pressure, doesn’t mean you should do it! — tubing, fittings, and the housings themselves can rupture, and are only as strong as the weakest link! (Think, cheap fitting, old/hard o-ring, scuffed/deep scratched tubing… or even just age/manufacturing defect on reputable parts!)

— these booster pumps typically can, and will be able to over-pressurize your system once it’s sealed off! they are regulated by an automatic shutoff switch (usually triggering @40PSI on the RO product water tubing, this will be built into your RO buddy, and is another potential restriction point!)

— as an aside, my system, with two 75gpd Dow Filmtec membranes @95PSI made right around 240GPD @ 1-2ppm TDS… I’m starting to realize that you’ll probably need to replumb your system to 3/8” tubing/fittings, up to the RO membranes, too! (The prefilter housings are typically 1/4” NPT, > in inside diameter than 3/8” tubing, so no need for new housings…)

— this is starting to look like a job for a custom system, or dual systems teed into one 3/8” line to the tanks, and one 3/8” line to waste! (Specifically, you’ll be moving around 1,800gpd for 1:2 product:waste ratio, or 3,000gpd for a 1:4 product:waste ratio… 1.25-2 gallons per minute!!)

Sounds like you and I have the same BRS RODI system, except you have the water saver. I bought mine in June of 2012 ( I just checked my order history on their site).

I was wondering many of the same points you brought here. I'm so glad you thought of them. Based on your insight, I did some research into how the waste / concentrate water is processed by the second membrane. I found this BRS Video that was another surprising thing I'm learning from this conversation. The video basically explains how running the membranes as a true parallel setup would double the input flow versus a single membrane. It also explains how using the two membranes in a series setup actually only slightly increases the input flow while almost doubling the output flow, which, if true, is awesome! It also shows how there is minimal pressure decrease. I think this video is saying I should be able to get away with a single booster running around 80 to 90 psi, but the proof is in the pudding. I trust your expertise, so I was wondering if it makes sense to you?



I also think I might want to go with 150 GPD membranes to get down below 1 gallon per minute to ensure the other items beyond the membrane have enough contact time.

I also realized that I have to buy these items with credit card points or they will cost me triple (my wife will justify what she calls a "fair purchase for her" which means when I spend $100 she feels that justifies her spending $200). I have to make sure I purchase from retailers that allow me to "Use Points" for the purchase. My wife once applied her rule to a purchase that hit the credit card but was paid through cash back points. The key is I have to keep it off the card altogether. The only good thing is that I get exclusive rights to our credit card points because all other disposable income goes to entertainment and gifts for her and the kids. So for every $1 of points I use, they get $20 of gifts and entertainment. That is how it has been for the last 18 years she has been a SAHM.

 

[kboogie]

I'm not keen on jumping into a thread to try to sell Buckeye Hydro products. If you have a specific question we'll try to address it.

Russ

Feel free to share your knowledge. I'm a big believer in the wisdom of the crowd.

 

[UncommonSense]

I also think I might want to go with 150 GPD membranes to get down below 1 gallon per minute to ensure the other items beyond the membrane have enough contact time.

Sorry, long day.. I’ll have to check the video out!

I decided to actually bother to to dig around for something resembling a legible flow chart for poly RO line, with little success… (lots of metric measurements)

So, please forgive the use of AI here to organize the pertinent data into a legible comparison!

As you can see, the flow rates you’re targeting are going to require a bit of consideration in the plumbing department… probably 3/8” for everything up to the RO membranes at 300GPD… maybe 1/2” for the long run to the tanks…

 

[mcarroll]

I’d personally recommend going through BRS or Buckeye hydro for these parts for several reasons:

I agree.

@kboogie If you are expert enough to spec your own system then maybe this route makes sense. But if the experience level is not there IMO save this request for your favorite RODI vendor or LFS. If you really want to shop Amazon, then find a good vendor on Amazon – simple!

If it helps, RODI systems cost close to $0 in the long run. For example, $350 / 10 years = $0.09/day...my unit is around 20 years old. Even though rodi gear seems like a lot of $ in the moment, pinching pennies up front doesn't net you much. For this reason, I'd pick a vendor and get what they say you need. That way you're done.

But if saving money up front is important for specific reasons (eg. cash flow) then IMO you'd be better off buying a used system and combining it with yours...but then we're back at the expertise question and whether that's the best route.

(There is no rule that says you have to be an rodi expert AND a reef tank expert – either one could be a full time job by itself! )

 

[Buckeye Hydro]

Feel free to share your knowledge. I'm a big believer in the wisdom of the crowd.

We've been designing/building/operating/selling RO and RODI systems for 26 years, so we've learned a thing or two. www.buckeyehydro.com

If you have a specific question I'll try to help.

Russ