Hey friends! So I thought I'd do a simple test today to see if my water filter really is removing chlorine, and if it is affecting other water parameters that I can measure with the test strips I have for my aquarium. I got a surprising result!


![](https://images.ecency.com/DQmeKN1yVEsn2a6a7BP7vMifhhokfvvWimgX5VgrHhT7bEm/img_20230105_222623.jpg)

So my water filter is a Pur brand one, and it says on the back that among other things, it removes chlorine. Since that is super dangerous to aquarium animals and generally city water has it in there as part of the purification process, I use dechlorinator when I do water changes in the aquarium.  I was curious to see what the difference would be between water straight from the tap vs. from my water filter.


![](https://images.ecency.com/DQmTpeJxPWua7UWEbgDdp8CgW6U7ug2YdXGh5AXf4DYTtKH/img_20221205_180938.jpg)

# Test #1: from the filter


![](https://images.ecency.com/DQmeAvXwChqkatTqYgcdRpS8h7g8TwdicKnkcwd9tGtTo9a/img_20230105_222752.jpg)

A low pH of around 6.4, no KH to speak of, a low GH (that's calcium and magnesium) of 25 mg/L or so. No nitrites or nitrates, and as expected, no chlorine. Fabulous!

# Test #2: from the tap


![](https://images.ecency.com/DQmaA7nQu8F6rF9UvwvyjgFF3UXXXpxF6njJximig7LR3cv/img_20230105_223009.jpg)

A slightly higher pH of 6.8, some KH this time at around 40 mg/L, somewhat harder GH at 75 mg/L, no nitrates or nitrites, but the surprise - no chlorine here, either! What? I want expecting that. And no, it wasn't sitting out so that the chlorine dissipated; I just filled the jar and tested right away.

This prompted me to do a little search and it seems Denver uses chloramine rather than chlorine:


![](https://images.ecency.com/DQmY4GMtiZqsJi5nQsstjcVCqNWPjx1VNagsgTn37rugvFX/screenshot_2023_01_05_22_58_34_640_com.ecosia.android.jpg)

So I still have to treat the water for my aquarium, as chloramine isn't good for them either, but I'm guessing that it doesn't read on the test strip checking for chlorine.

So it seems, other than the things my little test strips can't check for of course (my filter also removes things like lead and certain pharmaceuticals that are common in the US water supply - [yes, really](https://www.americanrivers.org/threats-solutions/clean-water/pharmaceuticals-personal-care/)), the main difference is that my filter removes some minerals in the water.

That's good to know, as my snails want more minerals for their shells but I don't want them too high for my betta - I have to strike a balance where it's acceptable for all of them. If I ever need to adjust one way or the other, it's good to know that tap water has more minerals, and filtered water has less.


![](https://images.ecency.com/DQmPeDW4d61X9RhxWY9y2MZTVrufyFyDjriobGFZoxTTnqG/img_20230105_223134.jpg)

Thanks for reading about my little science experiment testing my water! What is your local water source like, do you know?