testing equiptment questions

just wondering what people are using for testing their aquarium
levels.
I got tired of trying to get the water right on the mark when testing
for amo, nit, etc. and got a hold of a few 2 tea spoon (10 ml)
needle-less syringes. they are relatively cheap, I guess sterile,
and I use them for different purposes such as dosing and sampling
leaving small chance of contaminating one with the other.
I guess my question is that; can anyone share any experience with using
their own testing methods. for example I went to my local aquarium store
and asked for sodiumthyosulfate(dont count on that spelling being right)
and the guy pointed to amquel. according to what I've read he was wrong
cause sodiumthy.. is meant for separating the chlorine and chloramine
thereby cuasing an amonia spike that is detectable on average tests
as opposed to amquel or any other cholrine treatment sold for the
hobbyst that make amonia undetectable and causing mysterious nitrite spikes.