NT Labs Aquarium Lab Multi-test Kit

After a lot of research, I eventually decided on this test kit from NT Labs.

The pros:-

• The kit covers 6 tests, NH₃ (3 reagents), NO₂ (1 reagent), NO₃  (2 reagents), pH (1 reagent), KH (1 reagent) & GH (2 Reagents).  10 reagents in total
• All the tests are liquid tests, including NO₃, which in some kits are a combination of liquid and tablets.
• The pH test is a broad range test covering 4-10.
• The instructions are very easy to follow.
• It comes with a syringe.  Maybe earlier versions didn't as the one with the 2 kits I've bought both had one that didn't really have a proper place in the packaging.  Quite likely added now following feedback.
• The packaging doubles as a test tube rack whilst doing the tests.
• Its made in Britain.

The big plus for me is the broad range pH test.  Most other kits have two tests for pH, low range and high range.  My level around 7.5 would mean I would need to use both or just one and waste one.

The cons:-

• The colour charts for NH₃, NO₂, NO₃ and pH only cover 7 values
• The tests for KH & GH require a number of drops of the reagents depending on water hardness.  For NH₃, NO₂ & pH, you need 5 drops of each reagent whilst for NO₃ its 6 drops.  Would have been nicer if the non-hardness tests were all same number of drops.
• The packaging says "200 Tests".  This is a bit like your ISP quoting an "up to" download speed.  The amount of reagent you use for KH and GH depend entirely on the hardness of your water so it's actually impossible to state an exact number of tests.

I'm not too bothered about the granularity of the colour charts for NH₃ and NO₂.  If they're not zero you've got a problem so the fact that other values are marked with exclamation marks or skull-and-crossbones doesn't add anything.

For pH, the colour scale is in units for 4, 5, 6, 7, 8, 9 & 10.  My tests show a colour a bit greener than the yellow of 7 but paler than the green of 8, so we record this as 7.5.

Only the NO₃ chart is a problem.  The colours go from clear to a deep pink shade in steps from 0,2.5, 5, 10,20,40 to 80.  This, therefore offers two possibilities.  If the test result is darker than one value but lighter than the next, you can either record it as the higher or, like we do, put it mid-way between the two.  Either way, IMO consistency is more important than actual value.  Provided its not off the chart at more than 50ppm above tap supply.

The reagent seem to last a long time.  I bought our first one in mid-December last year for <£21 from Amazon.  I've just run out of Reagent-B for the GH test.  This is to be expected as we have GH of 15 so need to use 18 drops every time.  We only test GH around once every couple of months.  We're also just about to run out of Reagent-1 of the two reagent NO₃ test.  I've just taken delivery of a second kit, also from Amazon, for <£24.  OK, its gone up £3 in 5 months but its still cheaper to buy as a kit since, for some reason, to buy the components separately costs a lot more than the complete kit.  You do though get another set of test tubes and a syringe which is a bit of a waste.  I haven't, as yet, found a way to just replace individual reagents without all the other unnecessary bits.

That particular brand of testing kit is as good as any other liquid-based home testing kit in the aquatic hobby. (Test strips are much less accurate.)  However, all these test kits are much less accurate than the testing ones used professionally - see the first line of the second post in this thread https://forums.thinkfish.co.uk/new-fishkeepers/should-i-test-for-nitrate/msg13453/#msg13453.