For the 1 in 10,000 dilution to test bleach %, a 2-step serial dilution of 1 in 100 is indicated (i.e. a 1 in 100 followed by another 1 in 100).
I've noticed that the recommendation is add 10ml TO 1 litre water to achieve the 1 in 100 dilution.
Doesn't that result in a final volume of 1010ml...