Pearl gouramis are slow, deliberate surface-and-midwater fish that read a tank by its cover: the more planted and shaded it feels, the more time they spend out in the open showing the pearly spotting and orange throat that make them worth keeping. A bare, bright aquarium produces the opposite fish, one that parks behind the filter and fades. Decor for pearls is therefore mostly planting, arranged by height.
Tall plants as the architecture
Vallisneria along the back and sides forms bending green curtains a gourami can slide behind and reappear from, which suits a fish that moves by appearing and vanishing rather than darting. Tall stem plants fill the corners, and a broad-leaved sword or large anubias mid-tank gives a lower canopy to rest beneath. Leave the front centre comparatively open so the pearls cruise in view, framed by greenery instead of walled in by it.
Because pearl gouramis are sizeable once grown, scale the planting up: small, sparse sprigs make a large fish look exposed. A few mature, tall plants read as shelter; a dozen tiny ones read as clutter. Root the tall species firmly, since a drifting plant bunching at the surface changes the light pattern the fish have settled under.
The surface: partly roofed, always reachable
Gouramis breathe air at the surface, so the top of the tank must stay accessible, but a partly roofed surface is where they are happiest. Floating plants over one third to one half of the surface dim the light, and their hanging roots give a male the anchor points he uses when he builds a nest of bubbles among them. Keep a clear feeding gap and never let floaters seal the whole surface, both for the fish's breathing trips and for your own access.
Decor should stay out of the top layer entirely. Tall ornaments that pierce the surface create obstacles on the exact route the fish travel most, so keep wood and stone low and let the plants own the upper water.
Driftwood and quiet midwater structure
A long piece of driftwood laid or arched low across the tank gives pearls a landmark to hover beside and a shaded underside to retreat to when the room gets busy. Smooth stones at its base and a dark substrate complete a layout that flatters their colouring. Skip caves and tubes meant for bottom fish if they crowd the floor, and avoid anything with fine sharp points that could catch their long, thread-like pelvic fins, which trail well below the body.
Keeping a slow tank slow
Their long trailing pelvic fins are feelers the fish sweep ahead as they move, one more reason every plant edge and ornament in reach of their cruising layer should be soft or smooth rather than fine and scratchy.
Arrange everything so maintenance disturbs one zone at a time: prune stems on one side this week, thin floaters next week, and vacuum the open front rather than dismantling the planted corners. Feed at the surface gap and watch both fish rise unhurriedly, a good daily check that the layout still feels safe to them. Logging the floater coverage and pruning order in KinsLe Family Sharing helps everyone keeping the tank preserve the same calm pattern the gouramis have learned.