Tropical Fish Forum
Tropical Fish Keeping Help and Advice => General Fishkeeping advice => Topic started by: Extreme_One on May 31, 2015, 07:45:49 PM
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I've found a cheap TDS Meter on Amazon: http://www.amazon.co.uk/0-9990ppm-Household-Hydroponics-Laboratory-Scientific/dp/B00MRLMG0M
Has anyone used one?
It measures PPM - will this ppm reading strictly equate to water hardness or is also measuring something else?
More specifically,, how useful would this be to me in my quest to keep tabs on the hardness of my water? Or should I just use a standard liquid kit to test GH?
(Planning on mixing tap water and RO water)
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According to my son when he worked for a water testing company, GH measures only divalent cations. In drinking water, these comprise almost exclusively calcium and magnesium ions. There are only trace amounts of other divalent cations. So GH testers measure only calcium and magnesium ions.
But drinking water also contains monovalent cations, anions of all valencies and non-ionic compounds. TDS measures all these as well - it stands for total dissolved solids. TDS meters are a better way of measuring the 'softening' of water with RO because fish that like soft water like all those other things to be low as well.
GH testers will do the job, but TDS meters are better for this purpose, just more expensive. People who breed uncommon apistogrammas would use nothing else as their tank water has to be perfect.
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Thanks Sue.
So I can spend less than a tenner for a more accurate device I can use again and again, or I could spend £8 or £9 for a finite number of less accurate tests.
Hmmm that's a tough one. :rotfl:
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To be honest, I've never looked at the prices of TDS meters. From reading on other forums I had the impression they were much dearer than that!
Edit:
Quick look on-line and I see you can pay well over £50 for some.
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Hopefully the cheap ones I've seen on Amazon are adequate for home-use. The reviews are fairly encouraging.
I imagine, like anything, you can pay a lot for professional grade equipment, but for occasional home-use something much cheaper will suffice. Oh, well it's not a lot of money to lose if it's not ideal.
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It's mainly the cichlid forums that talk about TDS meters. Some of the south American cichlids need very soft, acid water to breed and those who want to specialise in breeding rare apistos, for example, would probably go for the most expensive equipment they can find :)
For general purpose use, the one you linked to should be fine.
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Thanks Sue. I certainly won't find it too much of a hardship to have a new gadget to play with! :))