PH problem? Or problem with test kit?

Question

I am using the Freshwater Master Test Kit to test my 10g aquarium.

Since day one - three months ago - I have had a weird problem happening.

1. When I check the PH using the low range PH test I get the highest value of 7.6.

2. Then I test the PH using the high range PH test and I get the lowest value of 7.4.

Has anyone else experienced this?

I've checked many times to make sure I am doing the test correctly yet I have this discrepancy every time...and no idea what the actual PH in there is!

Thanks.

Answer 1

this is typical and these tests are not exact.  It is merely a range and the color is subject to interpretation.  For the type of test this is, I would say that it is as accurate as it can be.  Ph is Ph, and the purpose of these two tests is to create and easy to decipher range depending on the type of tank you keep.  For tropicals, which should range from a Ph of 6.4 (discus) to 8.4, you would use the low range.  For cichlid and brackish tanks,which should start around the 8.0 range, you would use the high range test.  Using both is not needed.  If you keep tropicals, your ph is at an acceptable range for casual hobbyists and is currently not a cause for concern.

Answer 2

Most consumer-grade test kits are inaccurate to a certain degree.

The important thing is for you to keep using the same kit to test the PH every time: stability is more important than an accuracy of a few tenths.

If the test kits are from the same manufacturer (or, even if they aren't...), they will use different chemicals in order to produce a color change.

Answer 3

if i were you i would get this i personally have this and i LOVE it is so easy. it will tell you when the ammonia is high and gives the pH 24/7 for 6 weeks and color changes when ph changes i highly recommend this.

http://www.petco.com/Shop/Product.aspx?f...