Do rocks in your tank make the pH rise?
It depends on the rocks. Calcareous rocks (those that contain calcium carbonate) will buffer the water in the tank and will increase both carbonate hardness and general hardness. Examples of these rocks are all types of limestone, tuffa, dolomite, marble, sea shells, and coral skeletons. If you want to see if a rock will affect your pH and hardness, get some hydrochloric acid and a dropper from a chemical supply house. Put a few drops of acid on the rock. Calcareous rocks will bubble and fizz when acid contacts them. If the rock does not react to the acid, it probably won't do anything to your aquarium water chemistry, either. They will generally raise the pH of water to about 7.8 or so. Above that pH, limestone/shells are hardly soluble, so they will have keep the pH at about that level, but won't raise it much higher. This is a good thing with African cichlid tanks, most brackish water tanks, and all marine tanks, because the pH of the ocean is around 8.2 to 8.4, and the pH of most of the Rift Lakes in East Africa is from around 7.6 (Lake Victoria) to 9.0 or a little higher (Lake Tanganyika). Lake Malawi has a pH varying (by place, not by season) from about 7.8 to about 8.5. Raising the pH and hardness is, of course, extremely undesirable if you keep soft-water fish, such as most of those native to rain forests. Examples would be Discus fish, Angelfish, most other South American and West African cichlids, most barbs and danios, some rainbow fish, most tetras, and most corydoras species. Examples of rocks that have little or no effect on your water hardness and pH (because they are insoluble in water) are granite, basalt, obsidian, quartz, gneiss, and slate.
Yes whether it is are living rock it'll elevate the PH. Are you preserving SW? If you're preserving recent then the rock will surely die and lift your ammonia stages and that's now not well. If you're preserving SW then slightly upward thrust within the PH is well. eight.zero to eight.four is the favored degree. LR will aid you reap that target with no buffer.
They can if they are some sort of Limestone or coral based rock. What happens is the rock slowly dissolves and the minerals in the water raise the hardness and hence the pH. For African cichlids etc thats generally a good thing. Ian
