Nitrate

 

What is nitrate?

Nitrate is produced by the beneficial bacteria in the pond and filters as they break down the fish's toxic waste products (ammonia and nitrite). Nitrate is not toxic to pond fish, but excessively high levels can affect their reproduction.

Why test for nitrate?

Nitrate is a plant nutrient. The more nitrate is present the greater the potential for plant growth. If insufficient plants are present then algae will begin to dominate in the pond. Ponds with high levels of nitrate frequently have problems with algae and blanket weed.

What is the correct nitrate level in my pond?

The level of nitrate in your pond depends on the nitrate level of the tap water (or spring water etc) feeding into the pond, the number of fish and the amount of food fed. High nitrate levels will lead to algal growth. A nitrate level of zero is ideal and implies a balance between waste produced by the fish and nutrients taken up by the plant life. Remember this plant life does include algae!

What do I do if the nitrate level is wrong?

Maintenance of a zero level of nitrate in a pond is extremely difficult. Most domestic water supplies have a low level of nitrate. The key to maintenance of low nitrates is regular water changes to dilute the build up of nitrate. Also, increasing the higher plant life in the pond should use up nitrate. This will lower the amount of nitrate available to algae.

How do I do the test?

Ensure the test tube is clean. Take a 5 ml sample of pond water into the test tube, preferably using a hygienic Easydip Water Sampler. Add 6 drops of the Nitrate reagent and then one Nitrate Disc. Replace the test tube cap and mix well to break up the nitrate disc. Wait 10 minutes, then compare the colour of the sample to the colour scale provided. Zero nitrate is represented by a colourless sample. Any hint of pink in the sample indicates the presence of nitrate in the pond.