My pond turned a bright green last week from too much feeding of the
koi. My test kits were throwing me into a panic. Everything was
registering way off the charts. Tried to buy new kits but the only
thing I found in both PetCo and PetSmart were the single bottle which
measures 5 tests in 1.I pitched a holy fit but went ahead and shelled
out the $19.95. This is the best thing to come along in many a year....
for me at least. Anyway my pond took about 4 days to clear but I was
able to measure all the parameters in a single ONE SECOND dip on a
daily basis.
The ease of it ... no bottles, no measuring, etc.

Nedra in Missouri
Zone 6