• Archives

  • Categories

  • Pages

Why do I need to test for carbonate hardness in my lake or pond? – Pond & Lake Q & A


Testing for Carbonate Hardness

Pond & Lake Q & A

Q: Why do I need to test for carbonate hardness in my lake or pond? – Jose in Michigan

A: A number of pond treatments, including some algae-control formulas and other herbicides, contain copper. In certain conditions, the copper chelate may break down and release copper ions, which could cause your pond or lake’s alkalinity to rise.

If you use these treatments in a pond or lake stocked with trout, koi or goldfish that are sensitive to high alkalinity levels, you need to test your hardness regularly to ensure the health of your fish population.

What is Carbonate Hardness?

Carbonate hardness, or alkalinity, is the measure of carbonate and bicarbonate concentrations in your pond or lake’s water. Alkalinity is a measure of the ability of a solution to neutralize acid without changing the pH. It both controls and maintains water pH.

Alkalinity is related to the amount of dissolved calcium, magnesium and other compounds in the water, so alkalinity tends to be higher in harder water. It naturally decreases over time through bacterial action that produces acidic compounds that combine with and reduce the alkalinity components.

In a pond or lake, the alkalinity of the water is critical to the health of the fish – especially for trout, koi and goldfish. For these fish, the carbonate hardness of your pond or lake must exceed 50 ppm for the fish to survive, ideally falling between 50 ppm and 200 ppm.

Testing 1, 2, 3

When you’re treating your pond with a product like Pond Logic® Algae Defense®, be sure to use a water hardness test kit, like Laguna Quick Dip Multi-Test Strips.

Carbonate hardness is measured in degrees (KH) or in parts per million (ppm). Because the water hardness test kit will give its results in degrees, you’ll need to convert your findings from KH to ppm to determine whether the levels in your lake are safe for your fish. Use this formula to figure it out: 1 KH = 17.848 ppm. So if your test kit reads 5 KH, you would multiply 5 times 17.848, which equals 89.24 ppm.

POND TALK: How often do you test your pond or lake’s carbonate hardness level?

4 Responses

  1. How can you change the alkalinity in your water to specifically increase it?

  2. So, okay I test it, then what do you do to correct the situation?

    • Annette,

      Good question. The carbonate hardness of your water is based on the water content in your area. For large ponds there is little you can do about the current level or carbonate hardness. Measuring your carbonate hardness is designed to give you the ability to make a decision whether or not to treat your pond (containing koi, goldfish or trout) with any copper-based product.

      Make sense?

  3. […] more: Why do I need to test for carbonate hardness in my lake or pond? – Pond & Lake Q & A – W… Share this on del.icio.usDigg this!Post this on DiigoShare this on RedditBuzz up!Stumble upon […]

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

Follow

Get every new post delivered to your Inbox.

Join 143 other followers

%d bloggers like this: