Sometimes it’s just easier to look at a chart and move on.  For more detail about a compatibility component visit the compatibility discussions.  These charts are for freshwater and saltwater fish providing a summary of the compatibility information and more.

Each chart can be enlarged and zoomed into to see a specific fish or compatibility value.

The pH Compatibility chart examines the water pH that fish prefer or do best under.  Generally the pH variance between fish species is very small, but becomes significant in the overall health of the fish and the presentation of their natural behaviors in breeding and socializing.  The pH range for fish generally falls between 5 and 9, about two points from neutral 7 pH.

Compatibility is represented as those fish that prefer the same pH level, or deviate not more than .5 points.  Incompatibility is represented by those fish that have a preference that separates them by a full point.  This chart is not intended to present the actual pH preference value  for each fish.

The compatibility score is as follows:

• 3: Highly Compatible (Both fish have the same pH preference) DARK PURPLE
• 2. Compatible (Both fish are within .5 pH of one another) PURPLE
• 1: Slightly Compatible (Both Fish have different pH preference) WHITE

Note: pH is one of the more important water chemistry values to be aware of.  The sensitivity of fish species to pH levels is significant.  Although a fish can survive in an aquarium with changing pH levels, they can do so for only a short time.  A fish’s health will rapidly deteriorate when in aquarium water that is not optimized for their preferred pH level.