RO System help

[Buckeye_Hydro]

looks a lot like my reef tank RO setup. with 1.5 gallons of evap a day mine sees plenty of use.
If I was concerned my mebrane might be bad I would replace it... This is what they look like. I believe theres only a few manufacturers of these despite many many brands. most use dow filmtec I believe as the membrane material.
https://www.ebay.com/itm/Best-Quality-RO-Reverse-Osmosis-Membrane-Filter-50-75-100-GPD-TFC-TW30-1812-2012/272507899287?hash=item3f72bc8d97:m:mruxyIXxazI8E6rhzMD9Kvg this one has a diagram explaining what filter does what.

https://www.ebay.com/itm/24-36-50-7...hash=item3add6f7001:m:mvIrAhmC96uVgBepecb6Hew

Based on 20+ years experience, I'll respectfully disagree. As an example, both those membranes you link to are not made with Dow Filmtec membrane sheet. One tip off is that they require higher pressure and have lower rejection rates. There are many membrane manufacturers around the world. Filmtec, made in the USA, is still the best.

 

[augiedoggy]

Based on 20+ years experience, I'll respectfully disagree. As an example, both those membranes you link to are not made with Dow Filmtec membrane sheet. One tip off is that they require higher pressure and have lower rejection rates. There are many membrane manufacturers around the world. Filmtec, made in the USA, is still the best.

I stand corrected. The ones I linked though were just the first two from the list. I stated that I believe there are only a few manufacturers and I still believe that to be true as dow sells them to many companies that put their own stickers on them just as the chinese or other foreign manufacturers do. or are all dow made membranes always sold as the same Dow branded filter?

this unbranded sears one seems to indicate otherwise.
https://www.ebay.com/itm/SEARS-Kenm...724836&hash=item33d02ee2a8:g:KR4AAOSwU-pXvdsV

There are a lot of membranes that are replacements for filmtec vs real ones now that I look closer. and I dont doubt what you say. the non dow ones appear to all say "technology from the usa" instead of made in the usa on them.


the real dow filmtec ones do appear to be about twice the cost over the ones that claim they are a "Replacement"they are still very reasonable though.
https://www.ebay.com/p/Filmtec-Ro-M...d=222536065704&_trksid=p2047675.c100005.m1851


https://www.ebay.com/itm/Dow-Filmte...911826?hash=item1c694fa612:g:bK8AAOSwYVBZrufC

 

[augiedoggy]

This is an RODI system - it is the DI stage that brings the RO water TDS down to 0 ppm. Probably overkill for brewing.

Russ

The system I bought like many advertised for reef tanks often has two outputs, one for the reeftank that goes through the DI and one that goes through an additional coconut fiber filter and bypasses the DI for drinking water... Ive read that the DI water would actually be more corrosive and is not a healthy choice for drinking or brewing although I'll admit thats about as much as I know about it.

 

[passedpawn]

This is an RODI system - it is the DI stage that brings the RO water TDS down to 0 ppm. Probably overkill for brewing.

Russ

Dang, you know your stuff! You're right, the link by the OP has two carbon blocks and not a DI stage. Derp.

 

[schematix]

I bought 2 100 GPD membranes off Amazon for a dirt cheap price that claimed to be filmtec. I suspect they are counterfeit as neither is in spec by a large margin. They are however sufficient for brewing.

 

[augiedoggy]

I bought 2 100 GPD membranes off Amazon for a dirt cheap price that claimed to be filmtec. I suspect they are counterfeit as neither is in spec by a large margin. They are however sufficient for brewing.

Good point , would not be surprised at counterfeits
The real test would be to buy one from an authorized dealer if one exists and compare performance... Ive always thought the performance varied quite a bit by both water quality and pressure.

The cheap membrane I have produces 002-004ppm water vs 152ppm for the unfiltered water.(bypassed the DI filter, I get 001ppm through it).. tested just now filters and membrane about 3 month old. I imaging the extra $10-15 would pay for itself for the saved water vs higher rejected water with the cheaper membranes but I think the specs for all of them are like car fuel mileage generated in a lab and not a representation of true average performance.

The truth is from what Ive read there is no real certification standards or regulated testing for water filter performance..

 

[ScrewyBrewer]

Membrane manufacturer's recommendation. Any membrane not used for a week+ should be removed and treated with a preservative. That's the textbook answer. Biofouling is the issue. Remember your membrane is soaking in dechlorinated water - there's no disinfectant left in the water by the time it reaches the membrane.

Russ

My SpectraPure CSP RO 90-AF system has an auto-flush feature that flushes the membrane with clean water before and after each use. No where in the user manual do I remember reading a potential for bio fouling.

 

[augiedoggy]

My SpectraPure CSP RO 90-AF system has an auto-flush feature that flushes the membrane with clean water before and after each use. No where in the user manual do I remember reading a potential for bio fouling.

Maybe it does random flushes even when your not using it? Or they just dont mention it because they dont have a solution for it?

 

[Buckeye_Hydro]

Fouling and Scaling are two of the big categories of things that happen to membranes. I wouldn't expect this to be a topic in an instruction set on a residential-scale RO unit.

 

[MaxStout]

I bought my RO system primarily for brewing water. But I don't brew every week. However, once you have a system, you find other uses for RO water. I have a gallon jug of it dedicated for my Keurig (RO is great for that--less descaling of the coffee maker!). I refill that gallon about every week, so my RO system gets its regular workout. Also, when I start up the RO system, I let the first quart or so go down the drain. That's been sitting in that final stage since last time and I'm a little belt-and-suspenders about things. Sure, a bit wasteful, but I'd rather collect freshly-filtered water to use.

Now that winter is here, I run my room humidifier. With RO water, no chalky deposits on furniture. So now I'm going through RO water much faster. Like I said, you find more uses.

 

[schematix]

Good point , would not be surprised at counterfeits
The real test would be to buy one from an authorized dealer if one exists and compare performance... Ive always thought the performance varied quite a bit by both water quality and pressure.

Performance does vary a bit based on temperature and pressure.

When i tested it back in July when my water temps were >75F and my pressure was > 60psi i was getting 162 GPD off of a 100 GPD membrane. My rejection was in the low 90s though for a membrane that is rated around 97%. With my feed water around 280 ppm i was getting about 25ppm out. Not really that great but plenty for brewing.

 

[Buckeye_Hydro]

We have a calculator on our website where you can enter your pressure and your water temperature and see what production you can expect from your membrane. Temperature and pressure have dramatic effects on membrane performance. http://www.buckeyehydro.com/calculator/

 

[MaxStout]

I have a 75 GPD unit (~3 GPH). In summer (water temp ~65F) I'll get close to the rated output with 60 PSI water. In winter (water temp ~48F), with the pressure about the same, the output will be more like 2.25 GPH. There's an inverse relationship between temp and viscosity.

 

[Buckeye_Hydro]

I have a 75 GPD unit (~3 GPH). In summer (water temp ~65F) I'll get close to the rated output with 60 PSI water. In winter (water temp ~48F), with the pressure about the same, the output will be more like 2.25 GPH. There's an inverse relationship between temp and viscosity.

SUMMER:

WINTER:

 

[brew703]

I'll bet it looks a lot like this one (it's for my fish tank). Same one you got, but with the TDS and pressure meter. It replaced a Kent unit I had for 20 yrs. So far it's working as expected. BTW, I get zero on the TDS output. I feed this from a water softener, so that might help.

View attachment 551087

Yep. That's the exact one. I added a gauge and thought about adding the TDS but so far haven't done that.
I've had the unit since Sept and my rejection rate is still 92-95%. I've accepted that but was hoping to be closer to 98%. I've also noticed that my water pressure increased about 5% since the summer. It was about 73 PSI now it's almost 80. I guess in the winter it changes however our winters here in the south are pretty mild. We rarely see temps below 45 degrees or so.

 

[Master]

I'm looking at RO being my next big "consistency" step as my city water varies wildly season to season. And short of buying a (rather pricey) test kit so I can see what's coming out of the tap TODAY, I'm at best, guessing at what I'm starting with.

I'm in Virginia Beach, VA. I brew in my unheated garage, so I have to worry about freezeup. For my biggest brew days, I need about 20-25 gallons (10 gallons finished, 14 into Fermentor.

The storage tanks get pretty expensive in the size range I'd need to let the RO run and have water when I need it relative to the cost of the system.

Anyone have it set up where maybe the night before, you have it start flowing into the HLT and MLT (jumpered together)

I was thinking this
http://www.buckeyehydro.com/auto-shut-off-valve-kit/ installed to shut off an inch or so below the to of my HLT, (MLT is taller) and have it start collecting water the day before.

Three main concerns:
1- Can that valve handle being exposed to the temps in a HLT (175ish to get the MLT to 170F for mash out, it's a HERMS system)
2-Since there's no disinfectant in the water, how long can it sit before things grow? MLT and HLT would have lids on but not airtight. Biggest concern is there's always a little residue in the MLT that escaped cleaning. I'd hate to come out in the morning and BAM funky water.
3-HLT is Aluminum. Any corrosion issues with RO and older aluminum pot? It's eventually going to get upgraded to SS, but that's a "when it breaks or I have $400 burning a hole in my pocket" upgrade.

To mitigate freezeup and membrane getting da funk from not being used for weeks, I was thinking of getting a smaller undersink tank and a RO Faucet in the kitchen and just move it to the garage for brew days, with appropriate valving installed for being able to turn 3 valves off, and popping off the John Guest style fittings and walking out the garage with it, and putting it in it's home there, hook up inlet, outlet to the tank valve, and the brine drain lines, purge a quart, and then leave it running.

 

[Buckeye_Hydro]

Can that valve handle being exposed to the temps in a HLT (175ish to get the MLT to 170F for mash out, it's a HERMS system)

No - so you would get one of our adjustable float valves and mount it in a horizontal piece that spans the top of your HLT.

Since there's no disinfectant in the water, how long can it sit before things grow? MLT and HLT would have lids on but not airtight. Biggest concern is there's always a little residue in the MLT that escaped cleaning. I'd hate to come out in the morning and BAM funky water.

Should not be an issue in that amount of time.

HLT is Aluminum. Any corrosion issues with RO and older aluminum pot? It's eventually going to get upgraded to SS, but that's a "when it breaks or I have $400 burning a hole in my pocket" upgrade.

The textbook answer is that you should have no contact between RO water and metal other than SS.

Not sure I follow your paragraph regarding how you want to configure the system - best if we worked those details out with you over the phone.

Russ
513-312-2343

 

[Master]

Russ,

I'm currently overseas, will be home in a few days. I'll have better info as far as water pressure and such when I can get home and measure it as well.

 

[Buckeye_Hydro]

We'll be here when you need us

 

[Master]

What info would be best to have to call in?

Water pressure
Most recent water report? "Dirtiest" season report (usually spring)?

 

[Buckeye_Hydro]

What info would be best to have to call in?

Water pressure
Most recent water report? "Dirtiest" season report (usually spring)?

The fact that you are on "city water" limits lots of potentially worrisome variables from the discussion. Please find out if your water supplier uses 1) chlorine, or 2) chloramines to your water as the disinfectant.

Russ

 

[ScrewyBrewer]

I've read where biofouling has more to do with treating waste water and/or the desalinization of salt water. In the typical home brewery application, where city water is the only water source, I don't see how biofouling would ever be an issue. Having already been filtered and treated with, chloramine or chlorine, before it enters the RO filter.

Having a TDS meter that reads total dissolved solids, on both the source inlet and the RO outlet sides of the filter, is also a worthwhile investment.

 

[Buckeye_Hydro]

In typical home brewery application, where city water is the water source, biofouling would never be an issue.

Agreed - but I'd characterize it as "less common." We have seen it multiple times over the years.

Having a TDS meter that reads total dissolved solids, on both the source inlet and the RO outlet sides of the filter, is also a worthwhile investment.

Absolutely. Without a tds meter and a pressure gauge you are flying blind in terms of knowing how the system is working and troubleshooting any issues.