I only have a bore well in my home, so I bought an 8-stage water purifier with RA and UV, which adds minerals to the water. The final water TDS is 44. I'm keeping tropical fish, such as guppies and angel fish.

Can I use it to fill my aquarium / fish pond? Will it cause any problems for the fish?


2 Answers 2


Theoretically, yes

Why theoretically? Well, because it relies on a number of other factors too. For example, you need to make sure that there is no chlorine or chloramine in the water because this will kill the beneficial bacteria that live in your substrate (sand / gravel) and filter. (It might be unlikely that a bore well has chlorine in but it's worth checking anyway).

You'll want to check that the water doesn't have high levels of nitrate or trace amounts of ammonia.

In short, there's more to water quality than TDS but it's a good indicator. I've used water in tanks that has a TDS of 180 and I've used water that has a TDS of 7. As Allerleirauh suggests, buy a test kit and test the water you intend to put in before you add it to the tank.


I live in Germany. The water quality is measured here in "Härtegrad". In our village we have 40° in the water from our water pipes. Like this site declares, is this 712 ppm (p-arts p-er m-illion of T-otal D-issolved S-olids -> TDS).

We use this water regularly (I assume once per month or more) to change one of three parts of the water in our aquarium (assumed 1000l). We have guppies too, but also black mollies and catfish.

For more information you could buy such a home test kit for water quality. So you can check your water for other things too, like ammonium or nitrate, which are difficult for fishes.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.