Water purity test. Samples of water being tested for their pH levels. All the samples seen here are alkaline (having a pH greater than 7). This indicates that the samples are of hard water. Hard water contains dissolved minerals of calcium and magnesium. The minerals are harmless,but can cause problems with plumbing | |
Licence : | Droits gérés |
Crédit: | Science Photo Library / MARK SYKES |
Taille de l’image : | 3543 px × 5315 px |
Model Release : | Non requis |
Property Release : | Non requis |
Restrictions : | - |