Difference readings with different test kits

[sehaasch]

I have a Taylor K-2006 kit that I use for everything except testing Bromine. I bought a Rainbow Lifegard kit that only tests pH and Bromine. When I tested pH using the Taylor and the Rainbow, I got drastically different readings. Taylor read 7.4 and Rainbow read above 8.4. The Bromine readings were also very high. So I bought another brand of Bromine/pH kit (Hydrotools Swimline). That also very high for pH and Bromine. Now I wonder if the Bromine reading is higher than what it actually is. However, I used a Aqua Check strip and also got a high reading. So I'm guessing the Bromine is accurate, but the pH isn't. Have you seen this issue before?


260 gal., outdoor, cartridge filter, well water.

 

[JamesW]

The 2006 is the best kit for all tests. The high bromine level is interfering with the ph test causing it to read high.

 

[JasonLion]

Different PH tests are buffered more or less effectively against chlorine/bromine interference. Taylor uses much more effective buffering, so it will still work at much higher chlorine/bromine levels than the Rainbow kit will.