test kits = bogus???

[dickhordishay]

So I have access to medical syringes, and I'm assuming their scale is more accurate than a vial's scale.

I have one test kit, from Sea Chem for alk tests, where the 5 ml vial is more than what the syringe says is 5 ml. I have another test, from API for ammonia, nitrate and ite, and ph, where 5 ml is actually less on the vial than what the syringe says is 5 ml.

So do I go by the actual 5ml, or by where their marks are on the vials?

[rbursek]

I do not know for sure but if the instruction say 5ml I would go by the syringe and see how your readings againts your gut feeling on how your tank is doing.
Bob

[bertoni]

I'd go with the marks on the vials. This issue has come up before, and it's very confusing. Test kits seem to have a fairly high rate of problems, unfortunately.

[rbursek]

Good find, maybe that is why some test kits from different Mfgrs read different. Maybe the mark is always put in the same place and glass thickness throws it off. How much off where they?
Bob

[dickhordishay]

I would say they were off +/- .5 ml's - which may or may not matter, but out of 5 ml's I would say somewhat of a concern.

[Billybeau1]

I have always had success in using the mark that the manufacturer supplies on the vial. Whether it is exactly 5 ml or not. :)

[SimilanRocks]

Yes I found it's accurate going with kit's measurement. It should be what they QC'ed the kit.