Matching species
What pH overlap can tell you
When two species have overlapping planning ranges, there is at least a shared pH window in the StockingLab data. That is useful for ruling out obvious mismatches, but it is only one part of water compatibility. Temperature, mineral content, acclimation history and long-term stability also matter, and different sources may quote different acceptable ranges.
Why stability matters more than chasing a midpoint
The overlap checker is not telling you to chemically force the aquarium to the mathematical centre of two ranges. Rapid or repeated pH adjustment can create more instability than leaving naturally suitable source water alone. If your stable water already falls inside the verified needs of the livestock, consistency is usually the more useful planning goal.
No overlap does not have a calculator “fix”
If the profiles show no shared pH range, the safest interpretation is that the pairing needs more research rather than an additive or adjustment product. Confirm the species data from specialist sources and consider whether the animals are genuinely suitable for the same system. The full StockingLab planner also checks temperature, adult size, behaviour and group requirements before presenting a community result.
Use measured water, not a guessed number
Test the water you actually intend to use and, where relevant, understand its hardness and buffering capacity. A single pH measurement can move with carbon dioxide and other conditions, so one reading should not be treated as a complete description of the aquarium's chemistry.