Phosphorus is one of the basic building blocks of living matter. It is present in every living creature, and in the water of every reef tank. Unfortunately, it is present in excess in many reef tanks, and that excess has the potential to cause two big problems for reef keepers. …
In many reef tanks, the only supplements added are calcium and a source of alkalinity (and all of the chemical impurities that come along with these additives and, of course, food). No others, it would seem, are mandatory for keeping many organisms.…
The primary supplements needed on all reef tanks are calcium and alkalinity. These are required because corals and other organisms consume them to form calcium carbonate skeletons. There are many ways to provide these supplements, with each type of supplement having some advantages and some disadvantages.…
Aquarists spend a considerable amount of time and effort worrying about, and attempting to solve, apparent problems with the pH of the water in their tanks. Some of this effort is certainly justified, as true pH problems can lead to poor animal health.…
Like the relationship between alkalinity and calcium, the relationship between alkalinity and pH takes many forms. One of the most important of these is simply that alkalinity is defined as the amount of acid necessary to change the pH of the sample to a specific value.…
A wide variety of organisms in reef tanks lay down calcium carbonate structures, including corals, mollusks, and algae. These structures provide a variety of functions, including protection and body support, and the process of calcification itself may increase photosynthetic efficiency.…
Calcium is one of the most talked about ions in reef tanks. It is critical for the formation of a variety of structures, including the skeletons and shells of many corals and other organisms. This article is the first of several that will provide a detailed chemical understanding of calcium in seawater, calcium in supplements of various kinds, calcium in biological structures, calcium in various types of rock and sand, the effect of calcium on other ions like phosphate, how organisms take up and deposit calcium, and the monitoring of calcium in tanks.…
Most reefkeepers know they need to measure alkalinity, and most know it has something to do with carbonate. But what is alkalinity exactly? Why is it important? How is it measured? What can confound alkalinity tests?…
Welcome to the surprisingly complicated world of specific gravity!
One question that every marine aquarist faces is the amount of salt to add to the tank. Most beginning texts choose to describe the salinity in terms of specific gravity, and go on to relate how one measures it with a hydrometer.…