# RO water: Fad or neccesary evil?



## Wolf6 (9 Dec 2021)

I've noticed a huge increase of people using RO water for their tanks. What has always held me back, aside from being lazy and the effort required, is the huge impact on the environment, where 1 liter of RO water leaves 4 liters of wasted water. I already feel very conscious about the weekly water changes for my tanks, using it to water my garden in summer, but that is a drop of water on a hot plate compared to the buckets being wasted on RO. People can get great results with RO water, but they can also achieve those results without them. What is your stance? Is it neccesary/a neccesary evil, or should we be more conscious about how wasteful it is regarding our supply of fresh water, and perhaps chose less demanding plants/plants better suited to our local water instead?
I feel that for instance in gardening, its more 'accepted' or common to say 'that plant wont grow here because of the soil so I'll pass on it' - chosing another plant with similar effect in its place. Whereas in aquatics we will move hell and earth to grow that one plant we have in our heads. Perhaps a mindshift in aquatics more geared towards 'what can I grow on my tapwater with minimal adjustments' is in order? I'm not out to be telling anyone what to do, just some thoughts I've been having lately


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## tam (9 Dec 2021)

It's not so much plants as fish. If you've got very hard water that's going to limit to some extent fish. And, even if you say that tank bred are more adapted, so they'll survive but not breed - are you then compromising health because they are apparently ok but have a shorter or less healthy lifespan.

Rain water is a good alternative - or cutting the RO back with the waste when remineralising, so you have less waste and then using for alterntives instead of just running it down the drain.


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## Conort2 (9 Dec 2021)

I only use it because of my fish. Used to use rock hard tap water before, there were some plants I couldn’t grow in very hard water but the list of species was very few. Most species will be fine unless you go for more specialist species like synoganthus, tonina, eriocaulon, some more picky rotalas and ludwigias.

I used to think RO was a pain but I’m used to it now and it is nice to have full control over my water. However there is the environmental aspect you mention which isn’t great.

Cheers


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## mort (9 Dec 2021)

I've always been on the fence with ro a little. I save as much water as I can and use rain water where possible to dilute our rock hard tap water but, and this is where I know I'll divide people, I see no real difference for the average low usage consumer peeing a few litres down the drain when the water company seem disinterested in saving water themselves. I completely get that freshwater reservoirs and wetlands are being drained in the average year (saw how much the reservoirs had gone down in the lake district this year) but just last week we had a main around the corner that wasn't fixed for 5 days. That's probably more water wasted than the average ro machine in a few lifetimes. It seems the uk averaged over 3 million lost liters a day a few years ago 

Reality Check: Have water companies cut leaks by a third?.

So although it's not seen as environmentally friendly and if we can avoid ro then it's great but I don't think it makes much difference in the grand scheme of things. When I used it I pumped the waste into rainwater butts outsides which were empty in the summer, then in the winter they were full of rain so I didn't need the ro. Now I barely have enough livestock to warrant the need for frequent large water changes, so the rainwater butts keep me going fine.

I also think that a lot of people we assume are using ro because their tanks look amazing, actually aren't. I'm sure I've read that aquarium gardens use tap water and I thought, hopefully he can conform/deny @Tim Harrison  used tap water and his tanks were always stunning.
I've never been into optimal plant growth or colour but there were very few plants I had that didn't do ok in rock hard water, I just changed because of the fish I wanted to keep.


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## Courtneybst (9 Dec 2021)

tam said:


> And, even if you say that tank bred are more adapted, so they'll survive but not breed


I would disagree with this to an extent. I've had several species that aren't 'matched' to my water live full lives and breed. Thing is, most fish we keep aren't matched to our water, even the commonplace ones like neons and cardinals. Stendtker Discus are a good example of this, and they're no less healthy than wild caught Discus.

I do however agree with you about the waste. It's a wasteful process but I won't condemn anyone that uses it. I've been tempted more than once!


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## Nick potts (9 Dec 2021)

It's wasteful no doubt and I try and use the wastewater as much as I can. The waste can be minimized by using booster pumps and multiple RO membranes which I have seen produce 1:1 water/RO. 

My tap water is already soft and lowish tds (70ppm) so I probably don't need RO water for the most part, however, I like having control over my water so use RO.


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## Angus (9 Dec 2021)

I got an RO because i want to mix saltwater for breeding nerites, and also because i want to be able to lower my KH.


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## Wookii (9 Dec 2021)

I understand that an RO system wastes water, and I’ve always accepted that using an RO system is less environmentally friendly that using straight tap water - but in my ignorance I’ve never actually sat down and considered why, and exactly what those environmental costs are. Can anyone fill in the blanks for me - what are the environmental costs?

I understand that the waste water goes back to the water works and requires processing before presumably being released back into the river, and I also understand that the replaceable carbon cartridges may not be recyclable and contain plastics and have a carbon footprint of their own. But I’m guessing I’m missing other things? Does anyone have figures in the actual energy/ carbon usage?


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## mort (9 Dec 2021)

I do think waste is the biggest thing we should all try and cut down on and for most of us with a smallish tank and a garden, it's fairly easy to reuse a lot of the water we produce. I use my water change water on my plants and it grows good vegetables. If I were to still use ro then all of it would get used in the summer and I could store a good amount in the winter, so does it then become environmentally unfriendly?
When I first started marines and did the weekly 10% wc the waste ro was pumped into a water butt that overflowed into my ponds vegetable filter. Strictly speaking it wasn't ideal but the pond plants liked it. Marines have also moved on in the last few years with waterchanges becoming  unfashionable but of course ro is still nedeed for top ups.


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## Wolf6 (9 Dec 2021)

You say back to the river, but most water doesnt come from rivers, but is pumped out of the ground. The amounts by which this is happening during dry periods in summer causes the natural waterlevel of the ground to drop further and further, meaning the roots of trees and forests can no longer reach, in turn making areas more dry and more susceptible to drought. Marshlands dry out, farmlands suffer and there will be fewer natural water butts as more and more water is pumped up. Normally during winter the level is replenished or at least partially but last summers have been so dry the levels still have not recovered, whereas consumption was even higher than usual because of the heat. For warmer European areas like Southern France and Spain this is even more of a problem as some regions go more dry and turn almost desert like. But even in the Netherlands areas like the 'hoge veluwe' are becoming too dry for certain types of trees.


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## John q (9 Dec 2021)

Wookii said:


> Does anyone have figures in the actual energy/ carbon usage?


Not specifically for Ro water but I believe the uk's water industry emissions account for around 1% of the our carbon footprint as a whole, the more water we use, the higher this percentage will go.

Regards the environment I suppose taking water out of rivers when the reservoirs run dry does happen and will happen far more frequently in the future. Also worth noting that the water we swill down the drain occasionally gets dumped back into the rivers untreated, which isn't good for our wildlife, again not specifically aimed at Ro.

I think it rests upon all our shoulders to try and minimise the amount of water we use/waste.

Having said that if we consider how much water is probably lost due to leaks in the system or consider manufacturing a t shirt probably uses 2500L of water it begs the question is Ro water so bad environmentally?

For the record I don't use ro water.


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## arcturus (10 Dec 2021)

Most pump operated RO filters operate with a waste ratio of 1:2 or lower. Is this water waste significant? Well, [1 Kg of bovine meat requires ~15.500 litres of water to be produced], which is equivalent to a consumption of ~300 litres of water per week during one year. It is a fact that RO wastes water, but the role of RO in reducing the overall ecological footprint is insignificant. I would be more concerned with the ecological impact of the fertilizers used in the hobby than with RO...


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## Wolf6 (10 Dec 2021)

arcturus said:


> Most pump operated RO filters operate with a waste ratio of 1:2 or lower. Is this water waste significant? Well, [1 Kg of bovine meat requires ~15.500 litres of water to be produced], which is equivalent to a consumption of ~300 litres of water per week during one year. It is a fact that RO wastes water, but the role of RO in reducing the overall ecological footprint is insignificant. I would be more concerned with the ecological impact of the fertilizers used in the hobby than with RO...
> 
> 
> 
> ...


I'm not saying you are wrong but saying 'they are worse' when compared to industry is a trusted way for people to feel like it is ok to do nothing to improve the world. I apologize if that sounds moralizing or something, that's not my intention.
How much does a global average even say when you look at the enormous regional differences? And how much faith can we even put in these figures, how were they calculated? How much do they mean when not everyone has meat production cattle in their area?
The following figures were calculated in my country by measuring water use so I have a decent amount of faith in these numbers.
The average dutch person uses close to 43000 liters of water yearly. If he has a fishtank with 200 liters you could say he wastes an extra 21000 litres, assuming he uses the average ro system with 1:4 production (that's the average I keep finding, I am sure there are better ones out there but also sure there are people using decade old ones wasting even more to compensate those) and 100% ro water with 50% change a week. That's close to 50% extra. 
Please elaborate about the fertilizers, as you may have another point to ponder about


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## Wookii (10 Dec 2021)

I agree totally that we must try and do everything we can as individuals to reduce waste and energy usage. I didn't appreciate that water treatment accounted for 1% of our carbon footprint, so that is a useful statistic @John q

I can only speak from my personal situation in that I use RO because I have no practical way of harvesting rain-water in my current home, and rightly or wrongly I want to run a soft water tank. For my own justification, I'm not a gardener, so I have never used a hose to water my garden as I see my neighbours doing thorough the summer - so I guess for the garden I am a 100% rainwater user. I am due to move house in a couple of months, and at the new property I will have much more scope to set up some rainwater harvesting and allow me to transition over to rainwater (which would be much more convenient and cost effective anyway).

That said, if we are looking to focus on our energy consumption, one has to question the validity of keeping a fish tank at all. I have thought about this recently as I arrive home to an empty house in the dark evenings and see two rooms completely illuminated by nothing but fish tank lights. Whilst we can obviously argue that waste RO water is potentially an avoidable add-on energy consumption cost, it surely pales in comparison to the energy drawn by the light, heater and pump alone which must be in excess of 75-100 watts an hour for a standard 60cm tank in a well heated home, and way more for larger tanks/multiple tanks with more lights pumps and heaters.

When you consider our tanks from a purely environmental perspective, it's difficult to see them as anything other than selfish energy consumption for aesthetic pleasure. To an extent as fish keepers we have to come to terms with that reality, or choose not to have a tank at all.


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## Tim Harrison (10 Dec 2021)

mort said:


> I also think that a lot of people we assume are using ro because their tanks look amazing, actually aren't. I'm sure I've read that aquarium gardens use tap water and I thought, hopefully he can conform/deny @Tim Harrison used tap water and his tanks were always stunning.


You're right @mort  both AG and I, and Clive have achieved excellent plant growth without using RO water, so it definitely isn't a necessary evil. But I guess it depends on your ultimate goal, and some folk like to experiment etc.

As for the environmental impact statistics. I always treat them with a healthy dose of scepticism. For instance, Friends of the Earth and Greenpeace are very fond of backing up their own sensationalist facts and figures by referencing reports they made up earlier, often masquerading as  peer reviewed literature.  Which it isn't.

We all consume and make choices that have the potential to impact the planet in a negative way, even Arne Dekke Eide Næss. I don't think he ever used RO water though.


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## John q (10 Dec 2021)

Wookii said:


> When you consider our tanks from a purely environmental perspective, it's difficult to see them as anything other than selfish energy consumption for aesthetic pleasure. To an extent as fish keepers we have to come to terms with that reality, or choose not to have a tank at all.


You're right wookii, factor in C02 usage and all that fancy tech we import from far Eastern countries then we as fish Keepers are surely contributing towards the decline of our beloved planet. 

The reality is that anything we humans do in today's "modern world" will have some effect on the environment, I think its how we try and balance this is whats important. 

For practical reasons I can't, and don't want to go off grid and live in a tipi, become self sustainable and have a near zero carbon footprint. Nor do I desire driving around in a 4L gas gusling car or collecting 100,000 air miles every year. 

I think as fishkeepers most of us will be more in tune with whats happening to our environment/planet, and suspect we'll do more than most to try and leave some kind of legacy that our kids will be proud of.

I think the energy consumption of our aquariums is rather insignificant when we look at the bigger picture in general, and not something we should beat ourselves up about.


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## Wolf6 (10 Dec 2021)

Of course energy use is another important factor, and perhaps partially why I keep my tanks and fish choices limited to species that prefer lower (19-24c) temperatures, but I started this thread more about the water waste than about carbon or energy waste. Living in a forest rich area surrounded by agriculture makes the effects of drought and the impact of water wasting very visible. For instance birch trees are slowly dying around here because their roots can't reach the water in the ground anymore for the last few summers. Oak and beech have deeper roots but even those are not doing great. Seeing this and going on vacation to France and Italy, and seeing large patches of dried out nature and seeing lakes and streams at lower then normal levels has in the past few years made me very conscious of my water use. Of course the lower levels of the streams is influenced by less snow in the alps and other mountains which is influenced by the carbon output and energy use, but yeah, my focus for the thread was about wasting water mostly  and if people use ro water for breeding specific fish I don't have issues with it either. But currently I see it being used as some sort of holy grail of succesful scaping, and I feel that for 2/3 of the people doing it is just because they see others do it. They are pouring money and water down the drain for very little actual benefit and its wasteful when we should be conservative with our water. 
If someone has tips on how to save on carbon and electricity use in regards to our hobby I am all ears btw!


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## mort (10 Dec 2021)

A lot of our water problems in this country and I assume it's similar else where, is because we get water when we don't need it and in the wrong places. You could say this is water mismanagement but it's pretty historic and thankfully is being looked at much more now. In the past we have straightened streams, removed upland water control methods and paved over lots of the ground. Whilst I agree using ro or large quantities of tap water all help to create a larger problems I don't think they have much of an impact on droughts. Our local broad system has stayed at normal "ish" levels even during really dry summers when the water table has obviously been low. I've never been sure why there isn't more pushing to create more water storage because we know we need it and it's not like other countries where we don't get the rain in the winter to replenish things.

As to your question I think a lot of the answer lies with everyone following the same trends until they know better, its perpetuated by lots of professional aquascapers afterall. It's drilled into everyone that for a healthy high tech you need to follow a fairly regimental course to grow plants optimally, without algae and if you stray from that course too much then you will run into problems. I would guess it's experience, or in my case laziness, that helps some of us move away from that more rigid path.


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## Geoffrey Rea (10 Dec 2021)

Wolf6 said:


> What has always held me back, aside from being lazy and the effort required, is the huge impact on the environment, where 1 liter of RO water leaves 4 liters of wasted water.



The initial outlay on an RODI unit, that runs three RO membranes in series, is worth it if you’re in this for the long run. 1:1 waste to product is achievable in any season in the UK with a booster pump combined with this setup.



Wolf6 said:


> People can get great results with RO water, but they can also achieve those results without them. What is your stance?



Depends on your outcome amongst other things. Also dependent on the tap water parameters. Personally, planning to plant and dose a tank according to water parameters is a pre-requisite before even getting the tank wet. Share the same water source as Aquarium Gardens, extremely hard water that will grow a lot of plants. Some species won't grow in those parameters though. As before, depends on your intended outcome.



Wolf6 said:


> should we be more conscious about how wasteful it is regarding our supply of fresh water



Well, it's a bit silly blaming RO for being wasteful. What about EI? You need massive water changes to make that system of dosing work. Tap or RO, you're pushing water through that system. Is how you dose the tank the next thing to be moralised by folks? You can moralise anything if you're so inclined...

Why flush the toilet with fresh drinking water? All those who flush the toilet more than once per day are evil!!! 😂🤣😂 Chuck a brick in the cistern of all your toilets, feel morally superior...



Wolf6 said:


> Of course energy use is another important factor



Do RO without waste, run your tanks smarter.

Here:


Three RO membranes that recycle the water resulting in 1:1
Tank water gets a week in the tank, then feeds the garden and house plants (two uses)
Waste water is collected in barrels, then used to wash cars, bikes, water the gardens in summer, cleaning and other tasks about the property
RO water is heated by starlight, the solar panels produce enough in the afternoons year round to heat the water if you pick a sunny day
All tanks have their photoperiod in the afternoons so solar energy covers their most energy demanding periods of the day for a substantial proportion of the year



Wolf6 said:


> the huge impact on the environment



Because of the commitment to using RO, can design a system so all product water that enters the tank gets two uses, water is heated using solar energy and not a drop of the 'waste' water is actually wasted. Total water usage would be the same regardless of RO or tap water tanks.

Perhaps the easiest solution that saves all this hassle is use rain water and remineralise to your desired spec. This would work here if only it rained frequently enough, but Cambridgeshire is not the county for this so RO is on the table for soft water setups. We do get a lot of sunshine here though so incorporating solar to run the systems is a no brainer. The building is also air conditioned and can be powered by the solar during the summer for free with no carbon penalty.

The elephant in the room here is that this all costs money. All depends on how much thought and expenditure you are willing to commit to keeping tanks really.


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## KirstyF (10 Dec 2021)

Wookii said:


> When you consider our tanks from a purely environmental perspective, it's difficult to see them as anything other than selfish energy consumption for aesthetic pleasure. To an extent as fish keepers we have to come to terms with that reality, or choose not to have a tank at all.



I’m inclined to agree with this on the basis that no-one needs an aquarium and therefore any water/power consumption is in fact an unnecessary ‘waste’.
Equally many of us don’t need pets, 2 cars, or even 4 kids, we choose to have these things. Harsh but true! 
So where we can reduce, ethically, we should try to reduce, and where we are able to take actions to benefit ‘nature’ it’s good to do that too. This may be in our aquariums or in our broader lives. 
I’m running 700ltrs, this is clearly not a positive environmental choice. I also fill my garden with insect friendly plants, log piles,  leave areas of it wild, smile at my nettle patches, feed the birds, have a natural pond, don’t use insecticides etc. Does it make up for the aquarium or my travel into London every week or my meat consumption, no of course it doesn’t. Does it salve my conscience? maybe a bit! 
Pretty sure we could all do a little better though (including myself) and every little helps and maybe threads like this might make us at least think about these things and that’s no bad thing eh! 😊


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## arcturus (10 Dec 2021)

Wolf6 said:


> Of course energy use is another important factor, and perhaps partially why I keep my tanks and fish choices limited to species that prefer lower (19-24c) temperatures, but I started this thread more about the water waste than about carbon or energy waste. Living in a forest rich area surrounded by agriculture makes the effects of drought and the impact of water wasting very visible. For instance birch trees are slowly dying around here because their roots can't reach the water in the ground anymore for the last few summers. Oak and beech have deeper roots but even those are not doing great. Seeing this and going on vacation to France and Italy, and seeing large patches of dried out nature and seeing lakes and streams at lower then normal levels has in the past few years made me very conscious of my water use. Of course the lower levels of the streams is influenced by less snow in the alps and other mountains which is influenced by the carbon output and energy use, but yeah, my focus for the thread was about wasting water mostly  and if people use ro water for breeding specific fish I don't have issues with it either.


Whether we like it or not, aquaristics has an overall negative environmental impact, starting from catching wild fish in their natural habitats to the water and energy consumption needed to operate a tank, especially a "high-tech" tank. The usage of RO water is certainly a negative factor but it needs to be put in perspective. 1Kg of meat uses 15.500 l of water. Unfortunately, using or not using RO water will barely make a dent in our overall ecological footprint, including on our <usage of water resources>.



Wolf6 said:


> But currently I see it being used as some sort of holy grail of succesful scaping, and I feel that for 2/3 of the people doing it is just because they see others do it. They are pouring money and water down the drain for very little actual benefit and its wasteful when we should be conservative with our water.


Well, the root issue is not RO, but the current concept of "high-tech" accelerated, social-media driven aquascaping. How many scapers are actually aiming to create stable ecosystems for a longer term? What we see today, is way too many people setting up high-tech tanks for a couple of months with the goal of taking a handful of fancy photos for social media, just to reset the tank and start again, with a brand new hardscape, substrate, etc.. RO is not what is causing a waste of resources...



Wolf6 said:


> If someone has tips on how to save on carbon and electricity use in regards to our hobby I am all ears btw!


- Buy livestock that is locally bred. 

Stop buying fancy rocks and pieces of wood that are sourced from the other side of the planet.
Go low-tech.
Make other changes in your lifestyle that will have a much larger impact on your eco footprint than aquaristics...


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## Carol (10 Dec 2021)

Having kept Discus in areas with hard water either a heavy metal axe unit or RO were really needed. Having also had Marines you had to use RO for top up. As you replenish nutrients in marines in other ways that was fine.
However if you use pure RO it has to be remineralised as its basically water with nothing in it🙄. We for the Discus used half tap and half RO. 
Depends I guess on what your tap water is like.


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