Advertised in USA Weekend.Does anyone out there have one and do they really heat a 1000 Sq. room?Model 500 costs$397 and model 1000 costs $499.
some crystals do ok, the problem with quartz is mostly that it often is found along with metals and has other things mixed with it. the effect on pH should not be a factor in most tanks that receive normal and correct maintenance.
Quartz will dissolve slowly and raise the pH. It is a very slow process. The chemical basis of quartz is calcium carbonate.
Quartz, the second-most abundant mineral on earth, is all but insoluble in water (the glass your aquarium is made of will actually dissolve faster). Therefore, it has no measurable effect on the pH of aquarium water. As Punkin Eater says, though, there is a possibility that there are inclusions (contaminants, more or less) in the quartz rock, such as metals or other minerals, that might have an affect on aquarium animals or plants. For example, copper, which is usually blue or green in its natural forms, is toxic to most aquatic life. Iron (usually red, brown, or black when in rocks) is also soluble, but harmless in moderate amounts. Some more exotic elements, like arsenic, might also be possibilities. I wouldn't worry too much about it, though. I've used quartz and quartz-containing rocks in lots of fish tanks with no apparent harm. By the way, the chemical makeup of quartz is silicon dioxide (SiO2), not calcium carbonate. Silicon dioxide is also the main ingredient of glass. Calcium carbonate is the main ingredient in limestone, chalk, marble, sea shells, and coral skeletons. Calcium carbonate is somewhat soluble in water (some forms of it more so than others), and it tends to raise the hardness and the pH of water.
