i find it hard sometimes to get the water at the test line. either to much or not enough and you jiggle back a forth till you get it. just wondering if you take a eye dropper and if you are shy of the line you add with the dropper and you can take out with it too. just wondering

Sounds like a good tip. Just make sure the dropper is clean and
dunk in the tank water like the test tubes need. B)

pm4
you right i always rinse my tests tubes befor testing

The TetraTest pH kits include a little plastic pipette, which I use to fill all my test tubes. It's far easier than dunking the tubes in the water and trying to get the level exactly to the line. An eye dropper will work just as well.

I just grabbed one of the disposable plastic pipets from chem lab for this exact purpose hehe

Ceridwen, I did the exact same thing! lol.

The tests are not that sensitive to water volume. pH is simply a dilution, as are some of the others. Since you are going by color, color intensity, and how opaque the water is (nitrate) you do want to have the measurement close, but worrying about the water's meniscus is being obsessive.

The curvature of the round glass tube causes more difficulty telling the readings than a slightly differing volume of test water. THese tests are simply not that accurate - they are "analog" not "digital" - leaving it open to individual interpretation. Do not expect them to give you exact readings. It gives you a suggested reading - "within an epsilon".

That pipette from the Tetra Test works fine - it automatically measures the correct amount for any of the brand tests on the market - not just Tetra test. Save the sucker and use it for everything.