There are currently several phosphate test kits on the market and many will measure down to the low levels of phosphate required to prevent algae problems.
The problem however with nearly all other test kits is that at the lower end it is almost impossible to differentiate between the different pale colour swatches due to extraneous light and reflection from other colours on the comparison card.
The new D-D test kit overcomes this by providing two flat bottomed glass test tubes and a black polystyrene block, which allows the user to look down onto the colour card without any stray light or colour to alter the perception of which is the correct reading.
The second test tube is used as a standard so that any colouration of the aquarium water does not affect the ability of the user to read off the concentration.
With the new kit it is now easy to measure phosphate levels within the range of 0.14 - 0.008 (P) which equates to 0.43 - 0.023 (PO 4 ).
D-D recommend that for marine aquariums the phosphate level should be kept below 0.046 (PO4 ), and for freshwater aquariums that it should be below 0.092 (PO4 ).
The test kit with its nice plastic case contains sufficient chemicals to carry out 100 tests after which time a refill is available rather than replacing the whole kit.
