# Another Rain Water Question



## AverageWhiteBloke (3 Feb 2013)

Just wondering if rain water would be any use for making up 4DKH? I'm due to knock up another DIY batch for my drop checker. I have no access to pure water by the means of RO or Deion. I did have an API tap water purifier but it was left unused for that long the water that came out was putrid and I decided to bin it. The water from my tap is so soft doesn't really seem much point in buying anything to remove everything just so I can get a gallon of pure water once a year.
I have a twin pod with a small micron filter then carbon in but to be fair I haven't used that for years either  probably needs new carbon in as well. Just been opting for aqua-safe for easiness.

I bought a ltr of jeyes de-ionised water from tesco but my test meter showed measurable TDS can't remember the exact figures I will double check but I'm sure it was around 54, my tap water is only 33  Less TDS coming out the tap than the so called pure. Not sure if other brands may be purer, was going to try a gallon from halfords.
Just been reading something Clive posted about collecting rain water and wondered if it would be ok for just to put a bucket out in the middle of the garden rather than run off from a roof, half hour after the rain started so most contaminants are already down? Would there be anything that would affect PH. Also makes me wonder if I can't just use my tapwater being so soft. The ph out the tap is 7.0 but I know it's quite heavy in phosphates which I think can affect PH.

Interested in what you think.


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## Ed Seeley (3 Feb 2013)

If you're maiing up the 4dKH water using a test kit then it won't matter what the TDS of the starting water is really as long as it's 4dKH when you're done.


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## AverageWhiteBloke (3 Feb 2013)

Even if there is something else in there which affects the ph? Does that mean I could use boiled cooled tap water?


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## dw1305 (4 Feb 2013)

Hi all,


AverageWhiteBloke said:


> Does that mean I could use boiled cooled tap water?


 Should be able to, if you pour the water off into a clean container when it has just boiled, it shouldn't pick up any carbonates as it cools down. If the conductivity is the same in the boiled, cooled water  as your tap water (you need to measure them at the same temperature) you didn't have any carbonate hardness in your tap water.


AverageWhiteBloke said:


> Just been reading something Clive posted about collecting rain water and wondered if it would be ok for just to put a bucket out in the middle of the garden rather than run off from a roof, half hour after the rain started so most contaminants are already down?


Would be fine, but it will take a long time to get much water, I think the water from a down-pipe off the roof will be pretty low now as well. Snow is very efficient at removing particulates from the atmosphere, and usually it takes a while for levels to creep back up, and I'd expect single figure TDS values.

cheers Darrel


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## AverageWhiteBloke (4 Feb 2013)

dw1305 said:


> Should be able to, if you pour the water off into a clean container when it has just boiled, it shouldn't pick up any carbonates as it cools down. If the conductivity is the same in the boiled, cooled water as your tap water (you need to measure them at the same temperature) you didn't have any carbonate hardness in your tap water.


Thanks very much Darrel. I will do as you say and see what the results are. Coming from an area with this soft water it seems pretty pointless using RO to eliminate whatever nasties are in there or the small amount of dissolved mineral. I don't keep over sensitive soft water fish anyway although looking at the price of deio and carbon filters for my twin pod it may prove more cost effective to use those instead of dechlorinator in the long run. The lack of mineral I should get a helluva lot of water through it before they would need changing.

My main worry was that even though there was little KH in the tapwater there may have been other things in there that would negatively affect a ph reading. Especially with using rain water which, living in the lake district is well in abundance. I reckon even just leaving a 5gall bin in my garden would put a gallon of water in there in no time. 
When the big snow storms were going on I did collect some freshly laid for putting in my shrimp tank but you need a lot of snow. I filled a 2 gallon bucket with it but when it melts you end up with very little and the next day it runs the risk of being contaminated by either salt spray or exhaust fumes so didn't collect anymore.

For the eco warrior though rain collection and putting plant cuttings in the compost bin has got to be the ultimate way to go. I even considered keeping cuttings and drying them out to be ground down into a dust I could use under the gravel in new set ups to get the ball rolling making thinks even more self sufficient.


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## dw1305 (4 Feb 2013)

Hi all,


AverageWhiteBloke said:


> My main worry was that even though there was little KH in the tapwater there may have been other things in there that would negatively affect a ph reading.


You can ignore pH, as you get towards pure H2O it becomes a less and less meaningful measurement.


AverageWhiteBloke said:


> For the eco warrior though rain collection and putting plant cuttings in the compost bin has got to be the ultimate way to go.


I've got a huge compost bin in the garden and that is why I use rain-water. I'm pretty tight with money as well so I don't buy much and most years my fish-keeping makes a profit, although this year I'll be at least £50 - £100 down.

cheers Darrel


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## AverageWhiteBloke (4 Feb 2013)

dw1305 said:


> You can ignore pH, as you get towards pure H2O it becomes a less and less meaningful measurement.


Cheers again Darrel, looks like tap water may be the way forward for me. I understand that the drop checker is not the most accurate of measures anyway but will do as a quick visual reference to any sudden changes. While we're on the subject of tightness  How do you feel about using tapwater as a reference point for calibrating PH meters? As well as keeping an eye on the drop checker I have been doing some ph tests to see what my profile looks like at lights on lights off. Rather than using up my bromo blue if I were to test the boiled cooled tapwater and it's usual ph is 7.0 could I then use the tapwater to calibrate my ph pen to 7.0? I appreciate that again this is no exact science because of the possibility of acid causing compounds in the tank water affecting the result. But if I correlate the two and say that at lights on the PH meter was X and that within an hour or so the of lights on the drop checker was also X then I can be fairly confident that at lights on I had enough co2.


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## dw1305 (4 Feb 2013)

Hi all,


AverageWhiteBloke said:


> How do you feel about using tapwater as a reference point for calibrating PH meters? As well as keeping an eye on the drop checker I have been doing some ph tests to see what my profile looks like at lights on lights off. Rather than using up my bromo blue if I were to test the boiled cooled tapwater and it's usual ph is 7.0 could I then use the tapwater to calibrate my ph pen to 7.0?


Nice try, but you have to use real pH buffers, they aren't even really the sort of thing that you can make up easily. You really need to calibrate the pH meter every time you use it (on pH4 and pH7), and store the electrode in the correct storage solution etc. My suspicion would be that most pH measurements people take, away from very highly carbonate buffered or real black water, are "pick a number".

cheers Darrel


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## AverageWhiteBloke (5 Feb 2013)

Thanks again, PH meters are fairly cheap these days I notice and a lot come with calibrating fluids. I have an old Hanna one that rarely gets used and hasn't been stored with the electrode in storage solution so it's probably about done. I revived it from one of them boxes everybody has in their house labelled miscellaneous fish keeping equipment.  Put some batteries in and used a 4dkh fluid I had that measured at 7.0 with a liquid test to check the meter was still calling that 7.0. I would say you're disgusted at that shoddy level of practice  

Can't say I've ever came across one with storage solution though. If I remember right the one I have was meant to be stored with the calibration fluid and only came with a bottle of seven calibration. The storage solution would dry out very quick in the cap so needed topped up once a week from what I recall.

Looks like I'm investing in a ph pen again but at least I've saved on the 4dkh water 
Edit* Are the calibration fluids re-usable or one time things?


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## dw1305 (5 Feb 2013)

Hi all,


AverageWhiteBloke said:


> Can't say I've ever came across one with storage solution though. If I remember right the one I have was meant to be stored with the calibration fluid and only came with a bottle of seven calibration. The storage solution would dry out very quick in the cap so needed topped up once a week from what I recall.


Depends upon the electrode, but it is usually just potassium chloride (KCl), have a look here: <http://www.coleparmer.com/TechLibraryArticle/550>. You can store the pH electrode in the KCl solution, or fill the  cap. 


AverageWhiteBloke said:


> Edit* Are the calibration fluids re-usable or one time things?


 You can re-use them a couple of times, they just need to cover the electrode, so you can pour a small amount of fluid into a small beaker.

The buffers are quite cheap to buy: <Buffer Solution | ph4, ph7, ph10 and ORP Buffer Solutions - UK>.

cheers Darrel


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