A siamese algae eater works for a living, moving from leaf to rock to glass with its sucker mouth rasping at algae and biofilm, and resting between shifts flat against a broad surface. Decorating for one means providing plenty of grazeable area at every height while keeping the long, clear routes this active fish patrols from morning to night. It is a working layout, not a showpiece with a fish added.
Broad leaves as both pantry and perch
Anubias is the standout plant here because its wide, stiff leaves are exactly what these fish like to settle on, resting at an angle while they graze the surface film. Sword plants offer the same broad platform higher in the water, and large cryptocoryne leaves serve smaller individuals. Plant these broad species where light reaches them well, since a light film of algae on a leaf is not a failure in this tank but part of the menu, within reason.
Fine-leaved and delicate plants get rougher treatment. A busy algae eater investigating soft new growth can fray it, and plants rooted weakly may be loosened by constant traffic, so anchor stems behind rocks or choose sturdier species for the busiest routes. Moss on wood survives well and traps the fine particles these fish pick through all day.
Rocks and wood laid along the patrol route
Long, smooth driftwood pieces laid lengthwise become highways: the fish graze along them, rest on their upper faces, and use the underside shade at midday. Flat-topped smooth stones do the same job at floor level. Arrange wood and stone in lines rather than piles so the grazing route runs the length of the tank, and avoid jagged rock that could abrade a belly pressed flat against it for hours.
Keep at least one broad surface deliberately unscraped during maintenance. Keepers who polish every leaf and stone weekly wonder why their algae eater haunts the glass instead; leaving the back glass and one rock face filmed gives it a standing food source between feedings of vegetables and sinking foods.
Open lanes for a fish that never sits still for long
Siamese algae eaters are group fish that cover ground, chasing, schooling, and investigating together, so the middle of the tank should stay largely empty. Push planting to the back and ends, keep decor low, and let the open water run unobstructed end to end. That space is also where you will judge whether the group is thriving, because settled fish cruise it constantly rather than hiding.
The lid is part of the decor
Expect the fish themselves to rearrange your judgements over time: the surfaces they rest on most develop the cleanest grazed paths, and a plant they ignore entirely may be sitting in flow or light they dislike rather than failing as food.
These fish jump, especially in the evening and when startled, so a close-fitting lid with gaps around equipment sealed is not optional equipment but part of the habitat. Check corners and cable cut-outs after every re-scape, because the layout change that opens a new escape gap usually goes unnoticed. Recording which rock and glass surfaces stay unscrubbed for grazing in KinsLe Family Sharing keeps the whole household from polishing away the algae eater's pantry during a tidy-up.