Glass vs plastic test kit vials - reliability - repeatability.

[Coraloliseffect]

Some of the Salifert test I use, like phosphate being the worst offender, all come with plastic vials. From my weak memory of chemistry class. Plastic was always frowned upon due to sticking residue. So has any owe switched to a glass ware instead? Or is there a reason why plastic is ok? (Salifert is so highly regarded but the tests seam so cheesy in commonsensical items. )

Was thinking of using some extra Red Sea glass vials. But the depth will be different per unit volume.
Where a test like phosphate uses depth for color for measurement.

Our tests are so variable as is , want to remove chances of contamination.

 

[mcarroll]

If any, the influence is negligible. Or at any rate, you'll run out of reagents and get a whole new kit before it builds up enough to matter. These kits are designed to be disposable.

If you were using permanent glassware, of course you'd want to take extra steps in cleaning.

FWIW, you could use any vials you want for the Salifert kits I'm aware of - depth is not a factor. All measuring is done with syringes and there is no shaking involved, only stirring/swirling. (I haven't used every kit.)

Phosphate in particular is really only useful as a "yes/no" test for whether you have po4 in the water or not, so I'd say go ahead and use glass here if you want too. It's almost impossible to discern the gradations of baby blue (is that light baby blue, or extra light baby blue? try the light in the other room!) that actually indicate the range with liquid phosphate tests. (Not just Salifert.) I can get about the same quality of info (maybe better) just by paying attention to algae growth in a tank. This is one reason that electronic po4 meters are so popular. (Though meters have their own quirks.)

-Matt

 

[Coraloliseffect]

Thanks for the input.

I if you want too. It's almost impossible to discern the gradations of baby blue (is that light baby blue, or extra light baby blue? try the light in the other room!) that actually indicate the range with liquid phosphate tests. (Not just Salifert.) I can get about the same quality of info (maybe better) just by paying attention to algae growth in a tank.

Lol so true.

 

[Shtiff1]

I use glass, less porous. Plastics seem to hold Alot of whatever was in them.