# RO Waste



## Mark Grigg (3 Apr 2018)

Ok I'm scratching my head here, I've fitted a new RO unit yesterday I knew there was a waste pipe however I wasn't really prepared for the amount of waste, the system has a regulator on the waste pipe which is shut off but allows a pin hole to remain open at all times, the only logic to me here is that this is to stop the system becoming over pressurised?

But why I ask isn't there a system you can keep plumbed in 24/7 and use as needed (for an auto top up in this instance) without having a constant loss of water.
I'm not a fan of wasting water, so this does grate on me somewhat so looking to see if I can improve this situation.

Mark.


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## Andrew Butler (3 Apr 2018)

Hi Mark,
It sounds like this is your first time producing your own RO water!
The best systems widely available will produce 1L of waste water for every 1L produced so in essence you only get 1L RO water from 2L of mains water.
A lot of systems will take 3L or more to make 1L of RO water.


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## Edvet (3 Apr 2018)

Improving the pressure over the membrane will increase yields and decrease loss, nut sure how this can be done in simple household systems. You can use the "waste"on 1) hard water fish ( middle america's), 2) pond, 3) garden plants 4) household water, just collect it


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## Mark Grigg (3 Apr 2018)

Edvet said:


> Improving the pressure over the membrane will increase yields and decrease loss, nut sure how this can be done in simple household systems. You can use the "waste"on 1) hard water fish ( middle america's), 2) pond, 3) garden plants 4) household water, just collect it


It appears not to be very efficient 1 litre of waste takes just over 3 minutes and 1 litre of clean around 8 minutes 
So the waster will produce 38,000 gallons a years based on these figures, which is just not ethical.


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## ian_m (3 Apr 2018)

Any RO system running from simple cold water mains pressure, will typically produce a ratio of anywhere between 5 to 20 litres of waste water to 1 litre of RO water, even more when water is cold. Typically 5:1 on 3bar mains pressure.

The main way to improve the efficiency, maybe to even as low as 1:2 (RO to waste) is to increase the incoming pressure with a booster pump.

For example.
http://www.ro-man.com/shop/pumps/ro-man-intergrated-pump-box-for-ro-systems-50-100-gpd.html

There are other types available as well.

As for turning off the incoming water when storage tank is full you need one of these.
http://www.ro-man.com/shop/pumps/auto-shut-off-kit.html

Remember to either test or dechlorinate your RO water !!!! as RO units are not 100% guaranteed to remove chlorine and chloramine. This is the one case, in fish keeping, where a chlorine and ammonia test kits can be relied to give reliable results, as there will be no other contaminants in the RO water.

The reason for this is chlorine (and chloramine) MUST be removed by a suitable carbon pre-filter in the 1st stage as they can damage the RO membrane an appear in the RO water. However chloramine is more insidious as the carbon pre-filter will break it down to chlorine and ammonia. If the pre-filter is old or flow rate is too fast the ammonia (and to a certain extent chlorine) will not be absorbed by the pre-filter and appear as toxic levels in the final RO water. This is why I saw my local fish shop testing the RO water for chlorine and ammonia. The ammonia (and chlorine) will gas off in 24 hours. Though if you get a positive chlorine result your membrane is now ruined. So either keep track of pre-filter life or test RO water or just add Prime (to dechlorinate and remove ammonia).


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## Mark Grigg (3 Apr 2018)

ian_m said:


> Any RO system running from simple cold water mains pressure, will typically produce a ratio of anywhere between 5 to 20 litres of waste water to 1 litre of RO water, even more when water is cold. Typically 5:1 on 3bar mains pressure.
> 
> The main way to improve the efficiency, maybe to even as low as 1:2 (RO to waste) is to increase the incoming pressure with a booster pump.
> 
> ...


Many thanks Ian, I've just ordered an automatic shut off valve from RO Man, this will do the job perfectly. I'll test the water once I'm up and running.


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## Danielm (3 Apr 2018)

Depressing isn't it!

you can buy a simple in-line pressure gauge for a few quid - this will give you some indication of the pressure your system is running under. As other have said however a booster pump really is the way to go.

I can run 25 litres in roughly 2 hours (pumped) - prior to this, in the winter it would take more like 5 hours  - (caveat that my unit lives in the garage, which is detached)

An alternative for your approach would be to house the RO in a separate container (i use a 25 litre drum that fits down the side of the tank and cannot be seen) and run it to the Sump via an ATU -


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## ian_m (3 Apr 2018)

Mark Grigg said:


> I'm not a fan of wasting water, so this does grate on me somewhat so looking to see if I can improve this situation


My metered water costs £3.20 for 1000litres, 0.31p per litre. Thus at say 6:1 waste to RO works out 2.17p per litre. Doing 50% of my 180litre will cost £1.95 and for 52 weeks is £100 a year in water...Ouch.


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## Mark Grigg (3 Apr 2018)

ian_m said:


> My metered water costs £3.20 for 1000litres, 0.31p per litre. Thus at say 6:1 waste to RO works out 2.17p per litre. Doing 50% of my 180litre will cost £1.95 and for 52 weeks is £100 a year in water...Ouch.


I have 475 litres to deal with, I'm going to aim for a 13% water change per week, 63 litres at 9 litres per day. I'm thinking of sending the waste to the garden plants.


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## Andrew Butler (3 Apr 2018)

Danielm said:


> a booster pump really is the way to go


+1 but if you are putting it on a float valve you would need an auto shut off for the pump too as I know has been mentioned but have seen forgot.

I might suggest if you are keeping at a constant level using a float valve that you think about possibly replacing it from time to time and letting it drain from time to time to free up the mechanism as I have seen quite a few stories of them getting jammed open and making lots of mess - If you can go 1 better and put an overflow in the storage container which also goes to mains waste.



Mark Grigg said:


> I'm going to aim for a 13% water change per week


I think most people on here will tell you 50% per week is good practice with planted tanks


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## Fiske (3 Apr 2018)

Andrew Butler said:


> I think most people on here will tell you 50% per week is good practice with planted tanks



Depends. If using EI in a high tech tank, yeah. If going lowtech, dirted or similar you can make do with much less. Also bioload has something to say here.


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## ian_m (3 Apr 2018)

Mark Grigg said:


> I have 475 litres to deal with, I'm going to aim for a 13% water change per week, 63 litres at 9 litres per day





Andrew Butler said:


> I think most people on here will tell you 50% per week is good practice with planted tanks


Generally with high tech planted tanks ie high lights, CO2 and EI ferts, 50% water change per week is recommended, to prevent organics buildup (and to a lesser extent unused ferts).

However you must mix your RO water with tap water or GH booster as 100% soft water is in fact dangerous in a fish tank. This is because RO water has no buffering capacity and the slightest addition of acid (or alkali) will result in massive quick pH swings, generally called a pH crash, which can be fatal to your fish. So either say mix 50% RO with tap water (assuming the reason you are using RO is because your water is hard, if your water isn't hard, why are you using RO ???) or add GH booster. Both methods you should aim for 4-8dKH hardness.


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## Mark Grigg (3 Apr 2018)

Andrew Butler said:


> +1 but if you are putting it on a float valve you would need an auto shut off for the pump too as I know has been mentioned but have seen forgot.
> 
> I might suggest if you are keeping at a constant level using a float valve that you think about possibly replacing it from time to time and letting it drain from time to time to free up the mechanism as I have seen quite a few stories of them getting jammed open and making lots of mess - If you can go 1 better and put an overflow in the storage container which also goes to mains waste.
> 
> ...



I'm going to run a small pond pump from a timer, just need to work out how long to set the timer for. ref the boost pump I'll see how it goes first.


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## Daneland (3 Apr 2018)

ian_m said:


> My metered water costs £3.20 for 1000litres, 0.31p per litre. Thus at say 6:1 waste to RO works out 2.17p per litre. Doing 50% of my 180litre will cost £1.95 and for 52 weeks is £100 a year in water...Ouch.


My local shop charges £3.50 for  25 liters, if I do only 20% WC (25 lt)  weekly I pay £182. I hate it. TDS of tap water is around 400.


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## dw1305 (3 Apr 2018)

Hi all, 
It also depends upon the amount of ions in your tap water, the more ions you have the greater the amount of waste water. To get the maximum yield you need soft water, a warmed supply and a booster pump.

I'm not saying it is an alternative for every-body, but rain-water is free and freely available. If you had enough storage you could have collected many 1000's of litres of rain-water over the last month off an average roof.

cheers Darrel


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## Andrew Butler (3 Apr 2018)

ian_m said:


> Generally with high tech planted tanks ie high lights, CO2 and EI ferts, 50% water change per week is recommended, to prevent organics buildup (and to a lesser extent unused ferts).


I'm pretty sure Mark is using CO2



ian_m said:


> why are you using RO ?


I think this is a good question! I just wonder if Marks experience is from a marine background where you need to use RO to top up. (not for water changes)



Mark Grigg said:


> I'm going to run a small pond pump from a timer, just need to work out how long to set the timer for. ref the boost pump I'll see how it goes first.


Just remember the productivity of your unit can vary from day to day.
If you look at Ians previous comment adding the booster pump should improve the efficiency of your unit which I think is a big concern of yours.


ian_m said:


> The main way to improve the efficiency, maybe to even as low as 1:2 (RO to waste) is to increase the incoming pressure with a booster pump.


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## Zeus. (3 Apr 2018)

Lucky for me at work I have no water meter but I do use a booster pump and have a deionizing resin filter too. Need pure water at work as machines won't work if TDS is above 40. Have a backup distiller too. Having issues with the RO unit as it happens ATM have replaced the booster pump was 7 years old need some new values also which I have ordered of e bay.


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## Mark Grigg (3 Apr 2018)

dw1305 said:


> Hi all,
> It also depends upon the amount of ions in your tap water, the more ions you have the greater the amount of waste water. To get the maximum yield you need soft water, a warmed supply and a booster pump.
> 
> I'm not saying it is an alternative for every-body, but rain-water is free and freely available. If you had enough storage you could have collected many 1000's of litres of rain-water over the last month off an average roof.
> ...


I do have 400 litres already stored which we don't use.


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## Mark Grigg (3 Apr 2018)

Andrew Butler said:


> I'm pretty sure Mark is using CO2
> 
> 
> I think this is a good question! I just wonder if Marks experience is from a marine background where you need to use RO to top up. (not for water changes)
> ...



I will be using CO2 for sure, as for the RO I do have more fish experience than plants which has covered virtually every fish you can think of over the years, I like not to shock a system and thus the RO made sense doing small changes via an auto top up and adding nutrients back in daily for the plants. plus the removal of chlorine and especially chloramine was a concern. I'm in a soft water area with neutral Ph.

I'll hold off the booster pump for now, the efficiency isn't great as mentioned, however it was the continuous waste when the float valve was closed which concerned me most, so with the auto shut off valve from RO Man, this will reduce the waste tremendously.


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## ian_m (3 Apr 2018)

If you have soft water why are you using RO ? Many people would die to have soft water where you can harden it up to your requirements (4-8dKH). My water is very hard, having come from a chalk aquifer and plants grow monstrously, fish reproduce like rabbits with what comes out my tap.

If going high tech, you will need at least 50% weekly water changes to remove waste organics. If left the organics build up quickly and algae quickly follows. If I miss a water change it is pretty obvious due to BBA appearing as well as green spot algae within a couple of days.


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## Mark Grigg (3 Apr 2018)

ian_m said:


> If you have soft water why are you using RO ? Many people would die to have soft water where you can harden it up to your requirements (4-8dKH). My water is very hard, having come from a chalk aquifer and plants grow monstrously, fish reproduce like rabbits with what comes out my tap.
> 
> If going high tech, you will need at least 50% weekly water changes to remove waste organics. If left the organics build up quickly and algae quickly follows. If I miss a water change it is pretty obvious due to BBA appearing as well as green spot algae within a couple of days.


Thanks Ian, I'll get a KH test done as it's a new house but only a few miles away from my previous so should be the same water, I'll also look to increase the water change although not sure if 50% is possible.

With a booster pump, how is it controlled? I'm trying to be as automated as possible, so if it's a manual exercise it won't fit with my plans, if it can detect pressure and will boost when the float valve opens, then it has a chance.
I do have an 11W UV on the system, which I'd hope will assist with algae spores???


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## Andrew Butler (3 Apr 2018)

There are many people on this forum who adopt all kind of methods so I'm sure more will comment differently.



Mark Grigg said:


> I'll also look to increase the water change although not sure if 50% is possible


Maybe a planted tank; at least a high tech one isn't right for you then.

If you have a 500L system then a 50% water change can be a chore but you can simplify things.
I have teed into the intake of my filter so the majority of time to drain water out I just turn everything off, connect a hose and open the tee up then use a vacuum to go over the substrate.
If you have a weir this wouldn't work for you but I'm sure you could fashion something to be removable from one of the pipes within your overflow box that then siphons water off and then you could let your filter sock catch debris and pump it out from the sump or plumb things up a bit different and have it divert to a waste somewhere the possibilities are almost endless.
@Zeus. is one person who I know uses something similar to me when topping up and uses a thermostatic mixer to control the temperature of water to top things up so simply plumb one up under a sink and run a hose to your aquarium or go one better and plumb it directly into your sump.

As Ian says why even think about RO if you have soft water already?
I think you might be trying to over complicate something which if you redirected your thoughts and efforts could be a lot simpler in design and more effective.

This is just my opinion from what I know and many others know far more than me.
Andrew


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## Kitbag (3 Apr 2018)

You can connect a second membrane which takes the waste from the first membrane to reduce the losses. This definitely requires a booster pump though.


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## ian_m (4 Apr 2018)

Mark Grigg said:


> With a booster pump, how is it controlled?


The pump box I linked previously to has pressure switch(s) in it. When you close your RO output valve the system pressurises and the pressure switch turns off the pump. Open the RO output valve and pump comes on automatically. It also has a low pressure switch to prevent the pump coming on if the input water supply stops.

If you are using a pump you can fit a second RO membrane (and filter ?) in the waste output to recover more RO water, but costs more as two membranes to replace at service time. 2nd membrane will have a shorter life due to being fed with "dirtier" water. Also will need two valves and top ups into your storage vessel as the two RO feeds are at different pressures.



Andrew Butler said:


> As Ian says why even think about RO if you have soft water already?
> I think you might be trying to over complicate something which if you redirected your thoughts and efforts could be a lot simpler in design and more effective.


Go to you water suppliers web site and see what they estimate your water hardness to be.

Here is mine from the Southern Water website. A dGH of nearly 16, so nearly liquid rock. RO would benefit me if I could be bothered for the faff factor required, probably at 2:1 RO to tap water to bring dKH down to 5 odd would be a fine start. Note that in rest of world (not UK) 16 dGH is classified as very hard. I do have a whole house water softener for showers and baths as without it everything gets covered in scale pretty quickly. Unfortunately house softener water has no place in aquariums as contains sodium.





Remember 50% weekly water change in a large tank is a faff and time consuming, especially the substrate and plant vacuuming required in a larger tank so anything you can do to make things quicker and easier (ie using tap water) is well worth doing. Look what Zeus has done with a thermostatic mixer valve for his 500litre tank.

Below is a picture of the weekly detritus I vacuum out of my tank. I syphon into a 40l plastic tub, before pumping out onto my front lawn.




I also use a water heater to preheat the 90l water I change. Though for years I just used non heated water, no problems, if anything the fish do appear to like to swim in the incoming cold water for some reason.
https://www.ukaps.org/forum/threads/water-change-heater-project.25877/


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## Kitbag (4 Apr 2018)

I can recommend:

https://www.osmotics.co.uk/pages/Contact-Us.html

The chap there is very helpful and happy to give his advice. He helped me with deciding on my set up.


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## Edvet (4 Apr 2018)

ian_m said:


> Below is a picture of the weekly detritus I vacuum out of my tank. I syphon into a 40l plastic tub, before pumping out onto my front lawn.


Why not add the detritus to your lawn? it's plantfood I water my plants with old tankwater too


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## Kitbag (4 Apr 2018)

My RO waste mixes with rain water in a series of water butts.  When the last one starts to get filled the excess goes to top up the pond.


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## ian_m (4 Apr 2018)

Edvet said:


> Why not add the detritus to your lawn? it's plantfood I water my plants with old tankwater too


I syphon into a 40l yellow bucket first, so I can see any fish fry that accidentally get syphoned out. Then pump onto front lawn, the whole lot including detritus. I have quite a green front lawn, in fact a circular area that my hosepipe reaches.


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## HiNtZ (4 Apr 2018)

I'm sure it's been said (didn't read through all the posts) but that is perfectly normal. The waste water carries the large deposits away before passing water through the membrane. Without this run off, the membrane would become clogged and damaged within a day or two.

My RO/DI system produces 75 litres of waste to every 25 litres of fresh made and takes 8 hours on standard mains pressure. It kills me to waste so much water and I tried to use it elsewhere, but the only thing it's good for if you can be bothered is flushing your loo with it. Forget putting it on the garden plants, or drinking it/giving it to animals - it's like liquid rock and can cause serious health problems.

This summer I will be installing a separate water tank in my loft to catch the waste water and use it 100% for my toilet flushes. Yeah I might go through a few ball cocks because of the limescale, but that's a minor.


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## Mark Grigg (4 Apr 2018)

Ok, here is my report from my local WA. Sorry its quite in-depth, however I'm hoping someone with good knowledge will be able to decide if my RO unit is needed or not? 

*Analysis* *Typical Value* *UK/EU Limit* *Units*
Hardness Level Soft No standard applies
Hardness Clark 2.72 No standard applies Degrees Clark
Hardness French 3.89 No standard applies French Degrees
Hardness German 2.18 No standard applies German Degrees

Other technical data here 

*
Hardness Results*
For most analysis, results are from samples taken at random in the water quality zone of your area. In some cases, results are from samples taken from water treatment supply points feeding the zone.
*Hardness Level*
Value Soft
Standard No standard applies
UK/EU Limit
*Hardness Clark*
Value 2.72
Standard No standard applies
UK/EU Limit Degrees Clark
*Hardness German*
Value 2.18
Standard No standard applies
UK/EU Limit German Degrees
*Hardness French*
Value 3.89
Standard No standard applies
UK/EU Limit French Degrees

*Data is for period 01-January-2017 to 31-December-2017
Water Quality Summary Report*
For most analysis, results are from samples taken at random in the water quality zone of your area. In some cases, results are from samples taken from water treatment supply points feeding the zone.
*1,2-Dichloroethane*
Average <0.09
Maximum <0.10
Minimum <0.09
UK/EU Limit 3
Units µg/l
Number of Results 48
Samples above PCV Limit 0
*Aldrin*
Average <0.002
Maximum <0.002
Minimum <0.001
UK/EU Limit 0.03
Units µg/l
Number of Results 48
Samples above PCV Limit 0
*Aluminium*
Average <10
Maximum 22
Minimum <5
UK/EU Limit 200
Units µg/l
Number of Results 38
Samples above PCV Limit 0
*Ammonium*
Average <0.015
Maximum <0.018
Minimum <0.012
UK/EU Limit 0.5
Units mg/l
Number of Results 38
Samples above PCV Limit 0
*Antimony*
Average <0.04
Maximum 0.05
Minimum <0.04
UK/EU Limit 5
Units µg/l
Number of Results 8
Samples above PCV Limit 0
*Arsenic*
Average 0.11
Maximum 0.14
Minimum 0.09
UK/EU Limit 10
Units µg/l
Number of Results 8
Samples above PCV Limit 0
*Benzene*
Average <0.04
Maximum <0.05
Minimum <0.04
UK/EU Limit 1
Units µg/l
Number of Results 48
Samples above PCV Limit 0
*Benzo-3,4-Pyrene*
Average <0.001
Maximum <0.001
Minimum <0.001
UK/EU Limit 0.01
Units µg/l
Number of Results 8
Samples above PCV Limit 0
*Boron*
Average <0.015
Maximum <0.015
Minimum <0.012
UK/EU Limit 1
Units mg/l
Number of Results 48
Samples above PCV Limit 0
*Bromate*
Average 1.17
Maximum 1.48
Minimum 0.94
UK/EU Limit 10
Units µg/l
Number of Results 8
Samples above PCV Limit 0
*Cadmium*
Average 0.01
Maximum 0.02
Minimum 0.01
UK/EU Limit 5
Units µg/l
Number of Results 8
Samples above PCV Limit 0
*Chloride*
Average 15.07
Maximum 18.63
Minimum 12.79
UK/EU Limit 250
Units mg/l
Number of Results 48
Samples above PCV Limit 0
*Chromium*
Average <0.1
Maximum 0.2
Minimum <0.1
UK/EU Limit 50
Units µg/l
Number of Results 8
Samples above PCV Limit 0
*Clostridium perfringens*
Average 0
Maximum 0
Minimum 0
UK/EU Limit 0
Units No. / 100ml
Number of Results 38
Samples above PCV Limit 0
*Coliform Bacteria*
Average 0
Maximum 0
Minimum 0
UK/EU Limit 0
Units No. / 100ml
Number of Results 204
Samples above PCV Limit 0
*Colony Count After 72 Hours at 22ºC*
Average 2
Maximum 77
Minimum 0
UK/EU Limit No abnormal change
Units No. / 100ml
Number of Results 76
Samples above PCV Limit 0
*Colour*
Average <0.53
Maximum 1.45
Minimum <0.19
UK/EU Limit 20
Units mg/l Pt/Co
Number of Results 76
Samples above PCV Limit 0
*Conductivity*
Average 127
Maximum 172
Minimum 102
UK/EU Limit 2500
Units µS/cm at 20ºC
Number of Results 38
Samples above PCV Limit 0
*Copper*
Average 0.0167
Maximum 0.0331
Minimum 0.0017
UK/EU Limit 2
Units mg/l
Number of Results 8
Samples above PCV Limit 0
*Cyanide*
Average <2
Maximum <2
Minimum <1
UK/EU Limit 50
Units µg/l
Number of Results 48
Samples above PCV Limit 0
*Dieldrin*
Average <0.002
Maximum <0.003
Minimum <0.002
UK/EU Limit 0.03
Units µg/l
Number of Results 48
Samples above PCV Limit 0
*E. coli*
Average 0
Maximum 0
Minimum 0
UK/EU Limit 0
Units No. / 100ml
Number of Results 204
Samples above PCV Limit 0
*Enterococci*
Average 0
Maximum 0
Minimum 0
UK/EU Limit 0
Units No. / 100ml
Number of Results 8
Samples above PCV Limit 0
*Fluoride*
Average 0.78
Maximum 0.88
Minimum 0.69
UK/EU Limit 1.5
Units mg/l
Number of Results 8
Samples above PCV Limit 0
*Free Chlorine*
Average 0.28
Maximum 0.56
Minimum 0.05
UK/EU Limit No abnormal change
Units mg/l
Number of Results 204
Samples above PCV Limit 0
*Heptachlor*
Average <0.002
Maximum <0.002
Minimum <0.001
UK/EU Limit 0.03
Units µg/l
Number of Results 48
Samples above PCV Limit 0
*Heptachlor epoxide*
Average 0
Maximum 0
Minimum 0
UK/EU Limit 0.03
Units µg/l
Number of Results 48
Samples above PCV Limit 0
*Iron*
Average <15
Maximum 50
Minimum <10
UK/EU Limit 200
Units µg/l
Number of Results 76
Samples above PCV Limit 0
*Lead*
Average <0.4
Maximum <0.4
Minimum <0.4
UK/EU Limit 10
Units µg/l
Number of Results 8
Samples above PCV Limit 0
*Manganese*
Average <1.0
Maximum 1.9
Minimum <0.3
UK/EU Limit 50
Units µg/l
Number of Results 38
Samples above PCV Limit 0
*Mercury*
Average <0.022
Maximum <0.022
Minimum <0.022
UK/EU Limit 1
Units µg/l
Number of Results 48
Samples above PCV Limit 0
*Nickel*
Average 1.2
Maximum 1.8
Minimum 0.7
UK/EU Limit 20
Units µg/l
Number of Results 8
Samples above PCV Limit 0
*Nitrate*
Average 2.76
Maximum 3.35
Minimum 2.19
UK/EU Limit 50
Units mg/l
Number of Results 8
Samples above PCV Limit 0
*Nitrite*
Average <0.005
Maximum <0.007
Minimum <0.004
UK/EU Limit 0.5
Units mg/l
Number of Results 8
Samples above PCV Limit 0
*Nitrite - Nitrate Calculated*
Average 0.06
Maximum 0.07
Minimum 0.04
UK/EU Limit <1
Units -
Number of Results 8
Samples above PCV Limit 0
*Odour*
Average 0
Maximum 0
Minimum 0
UK/EU Limit Acceptable to Customer and no abnormal change
Units Dilution Number
Number of Results 76
Samples above PCV Limit 0
*PAH*
Average 0
Maximum 0.01
Minimum 0
UK/EU Limit 0.1
Units µg/l
Number of Results 8
Samples above PCV Limit 0
*Pesticides Other*
Average <0.004
Maximum 0.019
Minimum <0.001
UK/EU Limit 0.1
Units µg/l
Number of Results 4368
Samples above PCV Limit 0
*pH*
Average 7.98
Maximum 8.98
Minimum 7.31
UK/EU Limit Min 6.5, Max 9.5
Units pH value
Number of Results 76
Samples above PCV Limit 0
*Selenium*
Average <0.04
Maximum <0.04
Minimum <0.04
UK/EU Limit 10
Units µg/l
Number of Results 8
Samples above PCV Limit 0
*Sodium*
Average 9.9
Maximum 10.8
Minimum 9.4
UK/EU Limit 200
Units mg/l
Number of Results 8
Samples above PCV Limit 0
*Sulphate*
Average 21
Maximum 28
Minimum 16
UK/EU Limit 250
Units mg/l
Number of Results 48
Samples above PCV Limit 0
*Taste*
Average 0
Maximum 0
Minimum 0
UK/EU Limit Acceptable to Customer and no abnormal change
Units Dilution Number
Number of Results 76
Samples above PCV Limit 0
*Tetrachloroethene and Trichloroethene*
Average 0
Maximum 0
Minimum 0
UK/EU Limit 10
Units µg/l
Number of Results 8
Samples above PCV Limit 0
*Tetrachloromethane*
Average <0.07
Maximum <0.08
Minimum <0.06
UK/EU Limit 3
Units µg/l
Number of Results 8
Samples above PCV Limit 0
*Total Chlorine*
Average 0.35
Maximum 0.65
Minimum 0.09
UK/EU Limit No abnormal change
Units mg/l
Number of Results 204
Samples above PCV Limit 0
*Total Organic Carbon*
Average 1
Maximum 1.5
Minimum 0.8
UK/EU Limit No abnormal change
Units mg/l
Number of Results 48
Samples above PCV Limit 0
*Total Pesticides*
Average 0.006
Maximum 0.022
Minimum 0
UK/EU Limit 0.5
Units µg/l
Number of Results 47
Samples above PCV Limit 0
*Total Trihalomethanes*
Average 30.62
Maximum 39.44
Minimum 24.4
UK/EU Limit 100
Units µg/l
Number of Results 8
Samples above PCV Limit 0
*Turbidity*
Average <0.09
Maximum 0.61
Minimum <0.06
UK/EU Limit 4
Units NTU
Number of Results 76
Samples above PCV Limit 0


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## Mark Grigg (4 Apr 2018)

PH Test from the tap (mid 7's), and from the RO (early 6)

​


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## dw1305 (4 Apr 2018)

Hi all, 





Mark Grigg said:


> Ok, here is my report from my local WA. Sorry its quite in-depth, however I'm hoping someone with good knowledge will be able to decide if my RO unit is needed or not?


That is pretty good water.  You don't need RO. 

You can just look at a few parameters:

The conductivity value maximum 172 microS, mean 128 microS, so not very many ions of any description.

It has very limited carbonate hardness (the 2.18 degrees German) and very little NO3 (maximum 3.35 ppm) etc. The pH is high because of the added NaOH (which probably accounts for the 10ppm sodium as well).

cheers Darrel


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## ian_m (4 Apr 2018)

Mark Grigg said:


> *Analysis* *Typical Value* *UK/EU Limit* *Units*
> Hardness Level Soft No standard applies


Says it all, almost as good as RO water . You are lucky.

I suspect you have also fallen to the must use a test kit syndrome.
https://www.ukaps.org/forum/threads/what-about-test-kits.52487/
It is unlikely (though might be true) the tap water pH is 6.0. Water companies raise the pH (by adding sodium hydroxide and others) to prevent lead pipes being eaten away. Could be interference due to the chlorine affecting the test kit. Also test kits don't really work, and should be ignored is dKH is below 4, which your water is. Test kit in bin please. 

You will need to harden it slightly to get it to maybe 4-8dKH, as your source water "is to die for" soft. Most test kits, pH pens do not work reliably (full stop !!) when water is soft, below 4-8dKH. Making it up to 4-8kDH gives you some buffering capacity to "buffer" pH changes if things start going wrong. (may also make you pH test kit read correctly).

Either use limestone base hardscape, add calcium carbonate, add some limestone sand to your substrate or add reminerlising salts.
http://www.theplantedtank.co.uk/RO.htm
https://www.aquaessentials.co.uk/se...h=544_40_229&zenid=cvajjf7vn112v12os4tsmi1uc5


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## Mark Grigg (4 Apr 2018)

ian_m said:


> Says it all, almost as good as RO water . You are lucky.
> 
> I suspect you have also fallen to the must use a test kit syndrome.
> https://www.ukaps.org/forum/threads/what-about-test-kits.52487/
> ...





dw1305 said:


> Hi all, That is pretty good water.  You don't need RO.
> 
> You can just look at a few parameters:
> 
> ...




God guys I feel a bit of a tool, I thought the RO would give me optimum water to start, however reading this and more research, I've probably created more of a problem for myself  Especially I understand the elements that the plants need more now, so it's looking like a switch in strategy now, auto top up from the mains and buffer the tank up. Spare RO for sale


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## Mark Grigg (4 Apr 2018)

Just a thought here, would there be any benefit to keeping the RO pre filter and carbon filter and bypassing the resin filter to feed the float switch?


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## ian_m (4 Apr 2018)

Mark Grigg said:


> Just a thought here, would there be any benefit to keeping the RO pre filter and carbon filter and bypassing the resin filter to feed the float switch?


Yes if it is a dechlorinating pre-filter, though I suspect the allowable flow rate won't be that high (same as RO unit).

You are better with one of these, that will have a decent flow rate.
https://www.osmotics.co.uk/products/2-Stage-Heavy-Metal-Removal-Filter-System-and-Dechlorinator.html

In the end I would just use tap water into large drum (maybe heat) add dechlorinator (add GH booster if you can be bothered) and pump into tank easy. Some people fill containers (say 25l) perched on top of a ladder so they can just syphon into their tank, no pumps needed. KISS Keep It Simple St**id and you will be more likely to do it and do it correctly.


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## Mark Grigg (4 Apr 2018)

ian_m said:


> Yes if it is a dechlorinating pre-filter, though I suspect the allowable flow rate won't be that high (same as RO unit).
> 
> You are better with one of these, that will have a decent flow rate.
> https://www.osmotics.co.uk/products/2-Stage-Heavy-Metal-Removal-Filter-System-and-Dechlorinator.html
> ...



Thanks Ian, I think the RO is pretty similar to the one on your link, I've taken the resin cartridge off and filling from the carbon exit, flow is very good, so I've turned it down at the tap. PH is

 back to normal.


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## HiNtZ (5 Apr 2018)

Mark Grigg said:


> PH Test from the tap (mid 7's), and from the RO (early 6)View attachment 114489​



Give it enough breathing time and that RO PH will work its way up.

Someone I met recently got the bug for tanks and went to the fish shop to ask "what's the best water" - where they gave him 150 litres of RO and he filled the tank with it and dumped the fish/plants in. Didn't say anything to him about how essential at least some minerals are so I topped him up with some GH boost and have a bone to pick with the shop when I go in there.

Anyway, as was said previously..... your water seems just fine. I'm a tad jealous in fact.


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## Mark Grigg (5 Apr 2018)

HiNtZ said:


> Give it enough breathing time and that RO PH will work its way up.
> 
> Someone I met recently got the bug for tanks and went to the fish shop to ask "what's the best water" - where they gave him 150 litres of RO and he filled the tank with it and dumped the fish/plants in. Didn't say anything to him about how essential at least some minerals are so I topped him up with some GH boost and have a bone to pick with the shop when I go in there.
> 
> Anyway, as was said previously..... your water seems just fine. I'm a tad jealous in fact.



Thanks HiNtZ that's interesting to understand and I'll keep note of that incase my Ph goes the other way.

Tank is now complete, the auto top up is working a treat, 1 x 21ltr change at 12:00 and 1 x 7ltr at 18:00 - 196 litres per week from a 400 litre aquarium (that is a guesstimate). Still needs to clear a bit and a few plants to add as we go. Now the water testing and waiting game begins.


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