A scientist holding an erlenmeyers flask and puts some chemicals into it to test the water hardness
A scientist in a lab putting some chemicals into an erlenmeyers flask due to test the hardness of the water - the water is soft and the content becomes blue
A man checking the hardness of the water in an erlenmeyers flask-the water is soft due to the blue color
A man checking the hardness of the water in an erlenmeyers flask
A young scientist mixes chemicals in an erlenmeyer flask
Somebody pouring fresh water into an erlenmeyers flask
A scientist putting some chemicals into an Erlenmeyer flask and mixes it...
Scientist checking erlenmeyer flask with chemicals and writing results
A scientist adds some water into an erlenmeyer flask
A scientist in a lab putting some chemicals into a test tube due to test the hardness of the water
Time-lapse of a man checking the hardness of the water
A person taking some samples from an erlenmeyers flask and puts them into test tubes