BECAREFUL because one test tube from one maker could be out by a few drops compared to anothers brand eg
Hagen's 5 ml and APIs 5 ml differ by two or three drops which will throw any test out massively.
um im in australia so we order from australia but theres bound to be SOMEWHERE in ur area to buy them. look at Doctors, Fosters and smith or Live Aqurium webs.
OR usually its 5 ml of tank water, you could buy a cheap medicine cup (or glass shot glass )and a 5 ml syringe from a chemist. measure the water out in a syringe and eject it into the cup/glass
I use the 5ml and 1ml syringes daily, when testing its easier, when medicating i can get the correct dose and when feeding frozen foods (Brine shrimp, blood worms, Daphina etc) I can determine how much a fish has had as not to accidentally over feed:
my 1ml looks like this:
This is the kind my bf uses to inject acid into his tank to kill pest corals, and dose to kill algae in the fresh water tanks:
these can be brought at chemists and vets, my dads a wildlife carrer so i swiped a few from his supplies he wont miss them ad the vet GIVES them to him, usually they are 50cents to $1.50 at the vet. my pet store sells the 5mls for $0.50