Formalin is more toxic in soft, acidic water and also removes oxygen from water so vigorous aeration most be applied. Each 5mg of formalin removes 1 mg of dissolved oxygen from the water. Malachite green is also more toxic at low pH as well as high temperatures.Malachite green has two forms depending on pH. The initial strong green coloured for prevails at low pH (acidic), while in alkaline water it is converted to a colourless carbinol form.ormalin is more toxic in soft, acidic water and also removes oxygen from water so vigorous aeration most be applied. Each 5mg of formalin removes 1 mg of dissolved oxygen from the water. Malachite green is also more toxic at low pH as well as high temperatures.
Excretory Systems. Photo by: krishnacreations. Most animals require some system to excrete the waste products of metabolism from the body fluids. Kidneys are the major organs of the excretory systems of humans and other vertebrates, but several other kinds of excretory organs occur in other kinds of animals.
Organs of the Urinary System. 1  As you can see from Figure above, the kidneys are two bean-shaped organs. 2  Ureters are tube-shaped and bring urine from the kidneys to the urinary bladder. 3  The urinary bladder is a hollow and muscular organ. 4  Urine leaves the body through the urethra.rgans of the Urinary System. 1  As you can see from Figure above, the kidneys are two bean-shaped organs. 2  Kidneys filter and clean the blood and form urine. 3  They are about the size of your fists and are found near the middle of the back, just below your rib cage.