# Reverse Osmosis System



## Lemonhands (24 Apr 2022)

Hi all,

I am looking into purchasing and RO System so i can cut my water (I live in Bristol and so have very hard water). The fish i stock are hardwater fish but even by their standards my water is right up there, so i just want to essentially soft water down my very hard water enough to bring it in line and hopefully improve qol of my fishy friends. I would usually just go to my lfs but theyll probably only stock one model and so will push that, so thought id ask here before heading down there this week.

Does anyone have any recommendations? Is there anything else i should consider/know before buying an RO system?


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## john6 (24 Apr 2022)

the two i have used are Osmotics and Vyair, both offer outstanding customer service and help in choosing the right set up, and both make excellent quality ro systems.
You cant go wrong with either company. chat to them and they will tell you exactly what you need.


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## Lemonhands (24 Apr 2022)

john6 said:


> the two i have used are Osmotics and Vyair, both offer outstanding customer service and help in choosing the right set up, and both make excellent quality ro systems.
> You cant go wrong with either company. chat to them and they will tell you exactly what you need.


Thanks @john6 will check them both out now and drop them a message


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## Kelvin12 (24 Apr 2022)

Just be prepared for the excess waste water.   I think it's about a 4 to 1 ratio.   Worth it though if you utilise the waste on the garden or lawn. 
Dirk


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## MichaelJ (25 Apr 2022)

Hi @Lemonhands,  First, how big is your tank, WC frequency and WC percentage? .. and what's your current GH and what GH level do you want?

Cheers,
Michael


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## Aleman (25 Apr 2022)

john6 said:


> the two i have used are Osmotics and Vyair, both offer outstanding customer service and help in choosing the right set up, and both make excellent quality ro systems.
> You cant go wrong with either company. chat to them and they will tell you exactly what you need.


I'll second both of those, and also throw Finest-Filters into the mix, (also known as finest aquatics). I built my own system from parts from all three of those (and also RO-Man), but I have researched RO units for years in my brewing roles, where they are actually not required for the vast majority of water conditions. If you have a variable water supply (like I do) and you need a stable supply, like we do as planted aquarists, then an RO unit can be really helpful.

1) get a pumped system, this ensures your production rate is pretty constant, and it's cheaper to do so at the beginning rather than add it on later.
2) capacity is measured in US gallons per day, which is only 3.875L rather than the UK's 4.5L, bear that in mind when determining your requirements ... also note that the capacity is measured at 20C, it falls off when water is cooler than this.
3) if you want pure water then you will need a 6 stage unit. This adds a DI stage after the membrane (and a carbon "taste" filter). I go from 130-150ppm TDS to 2ppm after the membrane, and the DI unit takes that to 0 ppm. If you are only "cutting" your supply water with a proportion of RO then a DI stage is not essential, but remember that ion selectivity is variable across the membrane. Silicates for example are only 65% rejected, whereas Calcium is 95-98% rejected.
4) expect to waste water. Domestic RO units run at anything from 1:2 to 1:4 permeate to brine, mine a dual (100GPD) membrane  pumped setup is currently running at 1:1, and produces 0.8L of pure water a minute.

The good thing is that these units are modular, so adding an additional membrane to reduce waste water,  or a DI unit can be done quite cheaply at a later date. This is mine attached to a 300L IBC container as storage. I'm currently building a surround for it.




I've just added that 7L Vyair DI resin chamber, and knocked the pre-filters off it's support.


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## Lemonhands (25 Apr 2022)

MichaelJ said:


> Hi @Lemonhands,  First, how big is your tank, WC frequency and WC percentage? .. and what's your current GH and what GH level do you want?
> 
> Cheers,
> Michael


I have multiple tanks, but I am waiting on a 345l to be delivered which is what I am looking to get the system for (I will use it on the other tanks too). My typical water changes are roughly 30% every week to ten days. I'll confirm my current GH/KH shortly


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## Conort2 (25 Apr 2022)

I’ve got a pumped unit from vyair, can’t fault it.


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## Lemonhands (25 Apr 2022)

Aleman said:


> I'll second both of those, and also throw Finest-Filters into the mix, (also known as finest aquatics). I built my own system from parts from all three of those (and also RO-Man), but I have researched RO units for years in my brewing roles, where they are actually not required for the vast majority of water conditions. If you have a variable water supply (like I do) and you need a stable supply, like we do as planted aquarists, then an RO unit can be really helpful.
> 
> 1) get a pumped system, this ensures your production rate is pretty constant, and it's cheaper to do so at the beginning rather than add it on later.
> 2) capacity is measured in US gallons per day, which is only 3.875L rather than the UK's 4.5L, bear that in mind when determining your requirements ... also note that the capacity is measured at 20C, it falls off when water is cooler than this.
> ...


Thanks, that's very concise, will certainly look into the options of reducing the waste water somewhat as would prefer to be more environmental where possible, so less water wasted the better. I'm sure i can dump some of it back into the garden but I imagine there is a limit to that in the long run before the concentration of minerals has an effect there too.
As you say, i'm only really looking to cut the water to make it somewhat softer than it is without having to add a load of chemicals (which is usually only a trade anyway), so hopefully a 4 stage will be fine for my purposes. I'll certainly double check the pumped system though.


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## Wookii (25 Apr 2022)

+1 for Vyair - great service from them, and my pumped unit has been excellent. Just don't automatically follow their cartridge replacement suggestions.

My unit took 18 months before the carbon filters became exhausted and I started registering chlorine on my Hanna tester, and my RO membranes are still fine as I'm getting the same 6ppm product water I did on day one. If I had followed the 'recommendations' I'd have already been through 6 additional carbon/sediment filters and two additional RO membranes unnecessarily.


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## MichaelJ (25 Apr 2022)

Lemonhands said:


> I have multiple tanks, but I am waiting on a 345l to be delivered which is what I am looking to get the system for (I will use it on the other tanks too). My typical water changes are roughly 30% every week to ten days. I'll confirm my current GH/KH shortly



@Lemonhands  OK, I see. Well, if your doing 30% of 345L/wk  thats ~100L/wk. If you only seek to cut say 5 GH off from say 15 GH you need about 33L of RO water weekly the rest being your tap.   The problem people usually runs into is storage of the RO water so you have to factor that in.  I got the 100GPD RO Buddie with the optional DI cartridge (the water comes in at 270 ppm and out at 2 ppm).  I am using 100% remineralized RO+DI water in both my 150 L tanks with weekly ~40% WC.  Making about 120 L/wk - its manageable, but I wouldn't want to deal with more than that.  

The efficiency is a function of temperature and water pressure:






Cheers,
Michael


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## Lemonhands (25 Apr 2022)

I'm currently deciding between:
4 Stage 75 Gallon Per Day Reverse Osmosis RODI System (and purchasing the additional pump)
and








						RO-100MP Pumped 4-Stage Reverse Osmosis 100 US GPD (375 Litres) Fish & Aquarium Water Filter System with DI Resin Stage
					

RO-100MP 4 stage 100gpd reverse osmosis water filter system including pump and colour-change DI resin stage for fish & aquariums.




					www.vyair.com
				




I'm not sure how relevant having the in-built pressure gauge is in the Osmotics one if you're using a pump? I didn't see it mentioned on the vyair one, but a video I watched earlier says you can use it as a way to identify when one of the filter materials needs changing? Not sure if anyone could clarify?

Thanks


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## Kelvin12 (25 Apr 2022)

Without high jacking this post how long can you store RO water.  I am imagining indefinatey.  

Dirk


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## MichaelJ (25 Apr 2022)

Kelvin12 said:


> Without high jacking this post how long can you store RO water.  I am imagining indefinatey.
> 
> Dirk


Whats the expiration date on the "distilled" water you buy at the grocery store?.... Well, if it's sealed and not exposed to sunlight I would say indefinitely as well.. but you probably do not want to keep it until the sun turns into a red giant, as not everything is removed by an RO unit - such as most organic compounds, bacterial microorganisms, or dissolved gases like CO2, methane,  radon etc.

Cheers,
Michael


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## palcente (26 Apr 2022)

I used finer filters and they were excellent.
If your pressure is on the low side, pumped system will reduce the waste. My 50gpd fills 50l tub in around 3hrs. You can get a drinking system and use it for both drinking water and aquarium water. 6 stage drinking systems may have remineralizer/odour&taste treatment which you don't want for aquarium, you want to branch out with a check valve and a Tee before them. RO DI stage is to remove the 1% that membrane didn't catch, not worth the hassle in my opinion,  others will disagree. Very hard water will wear your membrane quicker, I would suggest getting the inline tds probe with the system, so you stay on top of that.

I use cheap plastic boxes with float valves which I fill overnight. Boxes are kept on DIY trolleys - just a piece of board with castor wheels. I then roll them out of sight and plop an airstone until next WC, so to answer the question above, water can last in a box for at least a week


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## Kelvin12 (26 Apr 2022)

Hmm less than I though.  I won't  bother storing it now just process as and when needed.  

Dirk


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## Wookii (26 Apr 2022)

Kelvin12 said:


> Hmm less than I though.  I won't  bother storing it now just process as and when needed.
> 
> Dirk



I've stored RO for weeks (probably 8 at most so far) with no ill effects. Lets be honest, if its in a lidded container, there isn't much that can really happen to it.


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## john6 (26 Apr 2022)

I used to store 1000 litres of rodi water in an IBC in my mixing station for months at a time, ready to make saltwater, still as good as it was when i filled it up. The key is to keep it sealed, not airtight sealed but as @Wookii says, keep a tight lid on it and out of sunlight, good to go.


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## Lemonhands (28 Apr 2022)

Not sure why I haven't been getting notifications for the post, but, thanks to everyone who contributed as i think I have made a pretty good decision, I ended up orderign the RO system today. I went with Osmotics in the end, mostly because i found the website the most user friendly and so finding what i needed was really easy. I did get a pump, plus the membrane upgrade kit (to cut down on waste water), I also got an inline TDS meter for it too.
Fingers crossed the set up all goes smoothly when it all arrives.

Thanks again everyone, been very helpful


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## Lemonhands (28 Apr 2022)

Also, I have this big plastic water canister thing which I take camping with me, so i'm gonna see if I can get away with storing some RO water in there, but it's not so big that it would store enough to cut my 345 outright, but some of my smaller tanks/the shrimp and neo rasbora tank I will also be setting up sometime it will probably do


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## Lemonhands (24 Apr 2022)

Hi all,

I am looking into purchasing and RO System so i can cut my water (I live in Bristol and so have very hard water). The fish i stock are hardwater fish but even by their standards my water is right up there, so i just want to essentially soft water down my very hard water enough to bring it in line and hopefully improve qol of my fishy friends. I would usually just go to my lfs but theyll probably only stock one model and so will push that, so thought id ask here before heading down there this week.

Does anyone have any recommendations? Is there anything else i should consider/know before buying an RO system?


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## Lemonhands (10 May 2022)

For those of you who may be interested in an update. This is by no means the finished set up, but proof that it works. I need to still tweak some pipe lengths etc


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## Miniandy (10 May 2022)

Aleman said:


> I'll second both of those, and also throw Finest-Filters into the mix, (also known as finest aquatics). I built my own system from parts from all three of those (and also RO-Man), but I have researched RO units for years in my brewing roles, where they are actually not required for the vast majority of water conditions. If you have a variable water supply (like I do) and you need a stable supply, like we do as planted aquarists, then an RO unit can be really helpful.
> 
> 1) get a pumped system, this ensures your production rate is pretty constant, and it's cheaper to do so at the beginning rather than add it on later.
> 2) capacity is measured in US gallons per day, which is only 3.875L rather than the UK's 4.5L, bear that in mind when determining your requirements ... also note that the capacity is measured at 20C, it falls off when water is cooler than this.
> ...


I would love to know how you've built this with a 1:1 ratio in mind. I was looking into this just recently and only just found out that 1:1 systems existed, my first RO unit had a reject rate over 5 😵‍💫


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## Aleman (11 May 2022)

Miniandy said:


> I would love to know how you've built this with a 1:1 ratio in mind. I was looking into this just recently and only just found out that 1:1 systems existed, my first RO unit had a reject rate over 5 😵‍💫


It's a series of compromises.

The dual membrane in series is one of the big keys to it. It's only something that you can do if you don't have a supply with  crazily high TDS to start with, because the first membrane concentrates the ions before passing it to the second. This does shorten the life of the second membrane, but by how much, is yet to be seen.

A pumped system is essential, and ideally the pump will be overated for the membranes, and self regulating (Keeps a constant flow for the pressure)

Use a flow restrictor on the brine outflow that is lower rated than "ideal" for the membranes. My 100GPD membranes should be using a 1200mlM restrictor, but I used a 800mlM initially, and got just below 2:1. I swapped it for a 500mlM, and was running at around 1.1:1. I have swapped down to a 300mlM restrictor  and that has brought it right down. However, as that happens the TDS of the Permeate/product line from the membrane increases. In my case at 800mlM I had 0ppm out of the membranes, at 500mlM it was 1-2ppm, and it's now 4ppm with the 300mlM unit. This has a cost implication as the DI resin is exhausted faster. I'll probably drop back down to 500mlM especially if I can find a Auto flush kit with that rating.


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## Miniandy (11 May 2022)

Thanks for the heads up @Aleman, really useful post


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## Aleman (11 May 2022)

Miniandy said:


> Thanks for the heads up @Aleman, really useful post


Not a problem, one useful source of information and tutorials (including testing setups) is Bulk Reef Supply on youtube, even if you can't buy the stuff from Australia


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## luckyfish (12 May 2022)

MichaelJ said:


> @Lemonhands  OK, I see. Well, if your doing 30% of 345L/wk  thats ~100L/wk. If you only seek to cut say 5 GH off from say 15 GH you need about 33L of RO water weekly the rest being your tap.   The problem people usually runs into is storage of the RO water so you have to factor that in.  I got the 100GPD RO Buddie with the optional DI cartridge (the water comes in at 270 ppm and out at 2 ppm).  I am using 100% remineralized RO+DI water in both my 150 L tanks with weekly ~40% WC.  Making about 120 L/wk - its manageable, but I wouldn't want to deal with more than that.
> 
> The efficiency is a function of temperature and water pressure:
> 
> ...


I'm considering to have a RO system set up as well. Storage of the RO definitely can be an issue.


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## brhau (12 May 2022)

*Waste ratio*: Though it's possible to reduce the waste ratio to 1:1, it will seriously degrade membrane life to the point where it's not economical (unless you have zero KH water). I personally don't think running dual membranes in series is worth it. By ensuring adequate pressure (up to 75psi) and using a flow restrictor slightly lower than the flow rate for the system, I can get the ratio down to 1:2.5. This is more than manageable for me to reuse all of it. I use it for filling the toilet tank primarily, but it can also be used in the laundry, for watering plants, etc.

*Booster pump*: Before investing in one, make sure you know the the pressure in your water line. Mine produces 90psi, which is too high for the pressure rating on the housings. I use a pressure regulator to decrease the pressure to 75psi.

*Storage*: I use 5-gallon carboys to store my water, since I don't have large volumes. Those with bigger tanks typically store in a Brute trash bucket. If you're storing for a long period of time, however, just be aware that the RO/RODI unit should be run at least every two weeks to keep the resin (if you're using one) and membrane wet. Otherwise, you need to remove the membrane and cartridge and store it in the refrigerator in a sealed bag with water.


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## Geoffrey Rea (12 May 2022)

Lemonhands said:


> I am looking into purchasing and RO System so i can cut my water (I live in Bristol and so have very hard water).



Osmotics:






Sediment filter, GAC filter, carbon block. 3x RO membranes in series with booster pump:





This takes Cambridgeshire Tap from 400-500 TDS down to 4-6 TDS.

Followed by two DI resin chambers this brings the 4-6 TDS down to 0 TDS.

After 15 months of service producing 300 litres per week the performance of the RO membranes is unaffected. It produces 1:1 waste to product at a rate of 50 litres per hour regardless of starting temp for all intents and purposes. The waste goes into rain barrels and will feed your garden year round.

Change out filters (sediment and carbon) every 6 to 9 months. DI resin is most effectively used by using regular DI resin for 90% of the cartridge and the last 10% colour changing. Changing DI resin every 2 months here.

You can wire in a TDS meter:





Layers of colour changing DI resin is good for early warning though.

The changing of filters on a schedule goes a long way to preserving the membranes. Even more importantly though, flushing your membranes for a couple of minutes prior and post producing product avoids a lot of cost. All Osmotics units come with a flush valve so this is very simple to do.

Tip: either disconnect the DI resin when flushing the main unit or fit a John Guest valve to direct flow to preserve DI resin. There is no need for DI resin to be involved when flushing RO membranes.


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## jaypeecee (12 May 2022)

Kelvin12 said:


> Just be prepared for the excess waste water.



Hi @Lemonhands 

It is particularly important to consider waste water if your supply uses a water meter.

JPC


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## Lemonhands (13 May 2022)

Luckily I am not on a water meter, but for the sake of not wasting water I purchased and extra membrane. I didn't realise that i wasn't able to post a video on my ast response, but I will post a picture when I next set it up again


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## Lemonhands (18 May 2022)

As promised here is a picture of the RO set up, as before its not the final set up as am going to rejig some of the tubing to make it a bit tidier, but will do for now!


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## Aleman (18 May 2022)

Love it, not sure you need to sort the tubing out, looks fine to me


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## Lemonhands (18 May 2022)

Doesn't remind you of the flying spaghetti monster much? That's all I can think of 


Aleman said:


> Love it, not sure you need to sort the tubing out, looks fine to me


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