Saltwater pearling normal after a water change?

Pearling after a water change can be normal in tanks with lots of photosynthetic organisms like algae or corals. When dissolved gases are replaced, rapid photosynthesis can cause oxygen bubbles, leading to pearling. Make sure your tank parameters and gas exchange are optimal.

Pearling in a saltwater tank, especially after a water change, is quite common—especially now that there are gorgonians, macroalgae, and corals in the mix. When you do a water change, you’re typically introducing water with higher oxygen and possibly higher CO₂ content. This, combined with the boost in nutrients and a clean environment, can ramp up photosynthesis. The visible bubbles (pearling) come from oxygen being produced faster than it can dissolve into the water, so it forms bubbles on the plants and sometimes on rocks or tank surfaces.

It’s also worth noting that agitation from the water change itself can temporarily increase the amount of dissolved gases. As the tank settles and the organisms adjust, the pearling usually slows down. It’s a sign that the photosynthetic life is healthy and actively producing oxygen.

Just make sure you’re not seeing any signs of stress in the animals—pearling itself isn’t harmful, but big swings in parameters (like temperature, salinity, or pH) during water changes can be. If everything else in the tank looks good and your water tests are in line, there’s generally nothing to worry about. It’s a neat sign of a lively, productive setup!