Pond Boss Forums GENERAL QUESTIONS Water chemistry Another lime question

Magnesium and Calcium are both alkalies and will not bond together at a chemical level. Magnesium and Calcium both will combine with Phosphates, nitrates, and clay particles tying up excessive phosphates and nitrates. Plants on the bottom can then break the bonds and use them as a slow release fertilizer.

Magnesium is like the fifth most abundant element found in the earths crust, and third most abundant found in sea water, and 10th most abundant in the human body. Calcium is the most abundant element found on earth.

You are correct in away by saying magnesium will keep calcium from precipitating out of a solution but so will potassium. What ever element that can help keep the ph up will keep the alkalies from combining with acids and falling out of the soluble solution.

Magnesium and Calcium are needed for any cell growth weather its a plant or animal. They both truck in nitrates and phosphates.

Dolomite lime has a ratio of about 50% calcium and 40% magnesium the rest is sodium and clay maybe some silica. (EDIT:) 50%-40% is closer to 1-1 but available at 2-1. This ratio is 2-1 calcium to magnesium and in some cases maybe good. I have always been told that a ratio of 7-1 calcium to magnesium is best. Excessive calcium is never a problem as the most abundant element on earth.

If in the fish bio world magnesium is more important than calcium then I may change my mind on the ratio. From my farm chemical background excessive magnesium is bad.