Pond Boss Forums INTRO Questions & Observations Water hardness

Looking for an explanation on how water hardness in ppm effects a lakes ability to support a bloom. Can you get a bloom with low hardness numbers and good (25 ppm and higher) alkalinity numbers?

BUMP

My well has very hard water with lime. Haven't had any problem with bloom. My water is around 20ppm.

Looking for an answer regarding soft water/low hardness.

Salex, soft water is not healthy for fish. The hardness, in Calcium and Magnesium form, is needed for bone and tissue growth. Often, getting a soil analysis and adding Agricultural Lime will bring your water hardness up. Ag lime will also help buffer wide pH swings that occur throughout a day, which in turn, reduces stress on your fish.

If your alkalinity is in the 20's and you have a "low" total hardness, chances are, your alkalinity is coming from less desirable or beneficial dissolved salts, such as Sodium Bicarbonate. You need Calcium and Magnesium as the predominate salts for the best overall production of fish.

Here is a good explanation..... http://www2.ca.uky.edu/wkrec/Hardness.htm

Sorry salex I misread your question.

Rex,

Thanks for the link. I had read that before and is a good explanation of how alkalinity, hardness and PH are related but different.

Ag lime raises both alkalinity and hardness. I generally use alkalinity of 20 ppm as a bottom number to support a bloom. What is the bottom number of hardness to support a bloom? And is it possible to have a good alkalinity number and a low hardness number. It seems to me, that when you have low alkalinity you almost always have low hardness. But, what is that ppm number that will support a bloom.

bp

Here is another source

SRAC

https://srac.tamu.edu/index.cfm/getFactSheet/whichfactsheet/112/