TEST TUBES. QUICK TIP

Those who use water test kits know how hard it is to fill the glass test tub exactly to the mark. Here is a tip I found on the internet - use a syringe. I bought a needless syringe with 10 ml capacity, which I use to squeeze the tank water into the test tube exactly up to the mark. As an alternative you can use a straw, but syringe still is the most convenient method.