# De-ionised water for fertilisers solution



## deeproots (13 Jan 2020)

Hi All - I recently made up a batch of all in one and I managed to get the local fish shop to give me a litre of RO water.  My tap water is extremely hard so can't use that.  All anyone sells is DI water (supermarkets, car shops etc.) for use with car batteries or for ironing.  Can I use that instead of tap water?  I can get distilled online but I'd rather buy from a shop if possible.

Thanks!


----------



## ian_m (13 Jan 2020)

Just use cooled boiled water from kettle. I have very very hard water and very furry kettles.

When doing a weekly water change I boil the kettle, make cup of coffee and pour rest of water a 1 litre plastic jug. By the time I have done the tank, the water is cooled enough to be poured into dispensing containers, containing the dry measurements of the EI salts. Quick shake and then stored in cupboard under tank until needed.

No messing around with RO etc, Tesco is generally the cheapest source for small quantities, if you really feel you should use RO water.
https://www.tesco.com/groceries/en-GB/search?query=deionised water


----------



## deeproots (13 Jan 2020)

Thanks Ian - I used to do that but I read the hardness screws with your fertiliser with precipitation of traces amongst other things. 

That tesco source looks good but I guess i was worried as it was DI they'd add something like salt to de-ionise it (like a water softener would) or god forbid some other compound which might be poisonous to preserve it. 

Labels tell you absolutely nothing about the content other than it's "de-ionised water"

btw - I add ascorbic acid to bring the PH down regardless and add potassium sorbate to preserve.

Update - I found the safety sheet for the same stuff on the cpc website.  As expected very little useful info (like whats in it.)

https://www.farnell.com/datasheets/416313.pdf


----------



## dw1305 (13 Jan 2020)

Hi all, 





deeproots said:


> Labels tell you absolutely nothing about the content other than it's "de-ionised water"





deeproots said:


> All anyone sells is DI water (supermarkets, car shops etc.) for use with car batteries or for ironing


Absolutely fine to use. 

There are all sorts of legal requirements if you have (any sort of) distillation unit, so all "distilled" water is really RO or DI water. 

Deionised (DI) water is water that has been through a Reverse Osmosis (RO) unit initially and then through a <"mixed bed ion exchange resin">, meaning that it is purer than RO water. 

Rain-water is another option, free and plenty of it at the moment. It is what I use at home, at work I use the DI water. 

If you have a conductivity (TDS) meter you can dip that in. 

I actually did that this morning.  Tap water (about 17dKH, but very low nitrate etc.) was 650 microS, the tank water was 130 microS, the rain-water was 50 microS and the DI water was less than 1 microS. 

We don't use out distillation stills any more, but in that case the water was <"somewhere in between 4 - 10 microS">. 

cheers Darrel


----------



## deeproots (14 Jan 2020)

Thanks Darrel - very useful


----------



## Niton (14 Jan 2020)

Sorry to butt in here but I was wondering if water collected from a dehumidifier would be classed as RO or de-ionised water.
I'm running one in the house regularly through the colder months and keep thinking it's a bit of a shame to pour away if it is possible to use it as RO.


----------



## dw1305 (14 Jan 2020)

Hi all,





Niton said:


> water collected from a dehumidifier would be classed as RO or de-ionised water


It is, I wouldn't be too worried about suggestions that it might be polluted (during the collection process) and have dust etc. in it. 

The easy way to tell would be to dip the TDS meter in it.

cheers Darrel


----------



## Niton (14 Jan 2020)

@dw1305 thanks for the advice.


----------



## ian_m (14 Jan 2020)

No you should never use dehumidifier for anything other than pouring away, as usually stated in instructions, as it will be heavily contaminated with bacteria, mould, spores, volatiles and all manor of crap filtered out from the atmosphere.


----------



## Niton (15 Jan 2020)

OK @ian_m I will bear that in mind too!


----------



## Akmaliano (3 Mar 2020)

deeproots said:


> Hi All - I recently made up a batch of all in one and I managed to get the local fish shop to give me a litre of RO water.  My tap water is extremely hard so can't use that.  All anyone sells is DI water (supermarkets, car shops etc.) for use with car batteries or for ironing.  Can I use that instead of tap water?  I can get distilled online but I'd rather buy from a shop if possible.
> 
> Thanks!


I use this method all the time, i.e. buy a few of those 2.5l jerrycans of DI water from supermarkets to make my EI solutions. Better than boiled water as I'd read somewhere that boiling water doesn't really get rid of all elements that can mess with the chemilcals you put into it. 

I quite like the idea of using rain water as Darrel suggested above. Might give it a try sometime.


----------



## Witcher (3 Mar 2020)

Boiled (generally very hot) RO/rain water for me - higher temp helps with ferts dissolution. I think tap water should be avoided - too many contaminants (P, Fe in various forms etc.) which may cause undesired reaction with ferts (precipitation etc.).


----------



## Sammy Islam (3 Mar 2020)

deeproots said:


> Hi All - I recently made up a batch of all in one and I managed to get the local fish shop to give me a litre of RO water.  My tap water is extremely hard so can't use that.  All anyone sells is DI water (supermarkets, car shops etc.) for use with car batteries or for ironing.  Can I use that instead of tap water?  I can get distilled online but I'd rather buy from a shop if possible.
> 
> Thanks!



I use DI water to mix up my EI ferts mainly because my tap water is very hard and has a lot of nitrates. I also like the fact that i feel like i have more control over what goes in my tank.

I usually buy 5L of DI water from halfords for £2-3.50 and lasts me a couple of months. I don't think i have had any problems and i only make up 1month batches at a time.


----------



## Jayefc1 (5 Mar 2020)

I use boiled tap water for my all in one solution I think the secret is to add the ascorbic acid first to lower the ph before adding the salts


----------

