What Do You Know About Pond Water?

Water is an amazing substance. A little over 70% of our planet is covered with the stuff, it’s essential for life, of course, and you obviously can’t have a pond without it – but just how much do you really know about it?

Here’s your chance to find out. Our quick quiz will let you test your watery knowledge with a few questions about its basic chemistry and how all of that science fits in with looking after your own garden pond.

Whether you’re a fully qualified water-genius already, or find out a few things you didn’t know before, it might just make you look at the wet stuff a bit differently from now on.

It really isn’t too daunting – it is supposed to be fun, after all – so give it a go.

Have fun – the answers are at the bottom.

1. What is the chemical formula for water?

a) H₂O
b) H₂O₂
c) HO₂

2. At what temperature is water at its densest?

a) –4ºC
b) 0ºC
c) 4ºC

3. Does warm water hold:

a) More oxygen than cold water?
b) Less oxygen than cold water?
c) The same amount of oxygen as cold water?

4. Why doesn’t ice sink?

a) It’s denser than cold water.
b) It’s less dense than cold water.
c) The plant stems hold it up.

5. Biofilters help to control the amount of:

a) Nitrogen in the water.
b) Hydrogen in the water.
c) Carbon in the water.

6. Water is said to be naturally around neutral pH – but what does pH measure?

a) Oxygen saturation
b) The level of dissolved nitrogen
c) Acidity or alkalinity

7. Over 70% of the earth’s surface is covered in water, but how much of it is freshwater?

a) 3%
b) 13%
c) 30%

8. Testing the water is an important part of pond maintenance – but how often should you do it?

a) Once a day
b) Once a fortnight
c) Once a season

9.Which of the following COULD be used as a cure for green water

a) Adding barley straw
b) Filter system
c) UV clarifier
d) Planting floating or deep-water plants

10. Which of the following is NOT a major factor in water quality?

a) pH
b) Water hardness/softness
c) Ammonia
d) Hydrogen
e) Nitrate

Answers

1. (a) It’s H₂O – which is just as well, since H₂O₂ is hydrogen peroxide!

2. (c) Water is densest at 4ºC, which is why ice floats.

3. (b) Warm water holds less oxygen than cold water – which is why over-stocking with fish can be a source of serious problems in the summer.

4. (b) Ice is less dense than water – a fact that is obviously rather good news for fish and all the rest of the pond-life!

5. (a) Biofilters help reduce the amount of nitrogen in the form of nitrates, nitrites and ammonia, present in the water.

6. (c) pH is a measure of acidity or alkalinity, and it’s not only used for water.

7. (a) Only about 3% of the world’s water is freshwater and only 1% is available as water – the other 2% is locked up as permanent ice. No wonder garden ponds are so important for wildlife!

8. (b) Once your pond has become established, testing it fortnightly should help you to keep the water in good health.

9. All of these can be used as a way to control algae, so 1 point for each individual correct answer – and give yourself a bonus point if you recognised that all 4 were possible cures.

10. (d) Hydrogen is not a factor in a pond’s water quality, but all of the others are – along with nitrite, dissolved oxygen and carbonate levels.