# PH Test Papers?



## Aqua sobriquet (30 Jun 2019)

Anyone use these? I just want to make occasional checks of the rainwater I’m using at the moment. I don’t use CO2 so not sure how much it’s going to change anyway. They sell PH4 to PH9 papers for a couple of quid on the auction site.


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## sparkyweasel (30 Jun 2019)

They are a bit rough-and-ready and rely on your judgement in comparing the colour against the chart. A pH meter is only a few quid, and the cheap ones seem to be perfectly ok.


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## dw1305 (30 Jun 2019)

Hi all,





sparkyweasel said:


> They are a bit rough-and-ready and rely on your judgement in comparing the colour against the chart.


They work, but they are a bit rough and ready, and as you get towards pure water they become less and less useful. You can <"specific range pH papers">, but they are quite expensive. 





Aqua sobriquet said:


> I just want to make occasional checks of the rainwater I’m using at the moment.


They won't help with this. If you don't have any carbonate buffering at all <"they will read about pH6">, but as soon as get even a trace of dKH <"they will read pH8.">

Although it won't tell you what the pH is, I still think you are better off with a low range conductivity meter, rather than a pH meter.

The advantage of conductivity meters is that:

They are much more robust, and straight forward, to use then pH meters.
You can make up your own calibration solution.
They don't need regular re-calibration.
The electrodes don't need regular replacement.
Even a £20 meter should give you a reasonably accurate result. Although it doesn't tell you what the pH is, it doesn't matter. If you have a conductivity value of 100 microS (64ppm TDS) then you don't have many ions of any description and you can add weak acids to reduce pH or weak bases to increase pH.

If you live on the coast you may get some Na+ and Cl- ions, if you live in land you can assume that most of the conductivity comes from Ca++ and CO3- ions picked up from dust etc. Our rain-water (Wiltshire) varies from about 150 microS (after they've cut the corn) to about 30microS in the winter. It is all limestone around us.

cheers Darrel


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## sparkyweasel (30 Jun 2019)

I didn't think about why you wanted to test, but Darrel is right, you don't really need to, unless there's something in particular you're worried about.
One of my water butts somtimes gets some ash in it from an incinerator, so I was worried about that pushing the pH up, but it didn't make any measureable difference.


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## Aqua sobriquet (30 Jun 2019)

I just wanted to see if the water was suitable for certain inhabitants. I’ve not seen conductivity mentioned for this, just PH. For most things it seems to need to be between around PH7 and PH8. I have no way of knowing what the stuff in my water butt is but I could add tap water if it’s too acidic.

This type of PH papers look pretty straightforward to read to me? Each paper has two patches that change colour.


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## alto (30 Jun 2019)

Decent test papers but need to be kept in low humidity, closed promptly, store cool and dim etc
(don’t touch anywhere near the reagent pads)

But as Darrel mentions, pH checking rainwater is much like pH checking RO water - TDS is a better quality check (ie provides more information)


Most online fish sites only report locale pH, sometimes this is all that’s measured (though if you go to the research papers, conductivity is often measured, in addition to qualitative observations) ... perhaps as pH is such a traditional parameter and lots of retail kits sold for same

Seriously Fish usually includes Hardness information, and published papers on newer profiles


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## alto (1 Jul 2019)

Aqua sobriquet said:


> For most things it seems to need to be between around PH7 and PH8.


I’m dubious about this, that looks like a generalization 

Most South American fish and many Asian fish come from acidic waters, sometimes as low as pH 3
Rift lake measurements are often above 8, or sometimes as low as 7.6 (depending on location, & season)

It’s more useful to do some research on the species of interest
Then consider how domesticated they might be, in which case, they may’ve been kept for generations in local breeding farm water 
Then ask local shop to check their tank water (ask for a sample to compare at home if they don’t regularly test tanks) 

If I’m buying a wild caught fish (or very expensive sensitive livestock), I’ll request a water sample separate from the fish and compare at home; rather than drip acclimating (which is always stressful for livestock) I’ll adjust my quarantine tank to match


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## Keith GH (1 Jul 2019)

Aqua

The only concern could be on how its collected and stored eg metal or old cement tiled roof and in an old rain water tank.

Keith


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## dw1305 (1 Jul 2019)

Hi all, 





Aqua sobriquet said:


> I have no way of knowing what the stuff in my water butt is but I could add tap water if it’s too acidic.


It won't be too acidic, but even if it read pH4 it would any need a very small amount of bases (H+ ion acceptors) for the pH to rise. You will have hard tap water, and even 10% tap will raise the pH well above pH7. 

I use a measuring approach, but just <"using the conductivity meter">, rather than a pH meter. 





Aqua sobriquet said:


> This type of PH papers look pretty straightforward to read to me? Each paper has two patches that change colour.


They are straightforward to use, but because you don't have many ions present (in rain water) you won't get much colour change. pH is a ratio, so it always needs some interpretation.





Aqua sobriquet said:


> For most things it seems to need to be between around PH7 and PH8.





alto said:


> Most South American fish and many Asian fish come from acidic waters, sometimes as low as pH 3


I agree with @alto, it really depends on the fish.

cheers Darrel


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## Aqua sobriquet (1 Jul 2019)

Keith GH said:


> Aqua
> 
> The only concern could be on how its collected and stored eg metal or old cement tiled roof and in an old rain water tank.
> 
> Keith



One water butt collects from a clay tiled roof the other from a plastic (shed) roof. All gutters are plastic and so are the butts.

I’ve been using rainwater because my tap water is quite hard and I really dislike the lime scale that collects on the tank and pipes etc. My tap water is 268 TDS, through the Inline Brita filter it comes out at 182 and the rainwater is 60. I have enough water (400L) at the moment for water changes for my 10L Nano but I’m not sure how long it will last when I set up my 35L.

The only inhabitants I’m considering at the moment is a few Corydoras and maybe some shrimp.


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## dw1305 (1 Jul 2019)

Hi all, 





Aqua sobriquet said:


> One water butt collects from a clay tiled roof the other from a plastic (shed) roof. All gutters are plastic and so are the butts.


Perfect. 





Aqua sobriquet said:


> I have enough water (400L) at the moment for water changes for my 10L Nano but I’m not sure how long it will last when I set up my 35L.


Can you physically fit another butt in? You can get kits to <"daisy chain them together">. 

cheers Darrel


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## Aqua sobriquet (1 Jul 2019)

Good point Darrel. There’s no space for another butt next to either of the existing ones but I may be able to place another one fed from the house roof. Once our patio makeover is finished in August I will look into that, thanks.


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