How to Aquascape an Open-Top Tank: Rimless Beauty
This aquascape open top tank guide covers everything you need to know to create a rimless, lidless planted aquarium that blurs the line between water and air. At Gensou Aquascaping, our studio at 5 Everton Park in Singapore, open-top tanks are our favourite canvas — they allow plants and hardscape to grow above the waterline, producing compositions impossible in a closed setup.
Why Choose an Open-Top Tank
An open-top aquarium removes the visual barrier of a lid and frame, giving you an unobstructed view from every angle. Rimless glass tanks — popularised by ADA, Do!aqua, and UNS — look like floating blocks of water on a cabinet. More importantly, an open top lets plants and driftwood extend above the surface, creating an emersed zone that adds height, drama, and a connection to the room’s decor. The result is part aquarium, part living sculpture.
Choosing the Right Tank
Rimless tanks made from ultra-clear (low-iron) glass are the gold standard. Brands like ADA Cube Garden, UNS, and Waterbox offer sizes from 20-litre desktop cubes to 300-litre showpieces. In Singapore, expect to pay SGD 50–100 for a quality 30–45 cm rimless cube and SGD 200–500 for a 60–90 cm tank. Standard float glass tanks with bracing removed also work, though clarity will not match low-iron glass.
Without a lid, evaporation increases significantly — especially in Singapore’s warm, air-conditioned homes where the humidity differential between water and room air is high. Choose a tank depth that tolerates a centimetre or two of water-level drop between top-ups.
Hardscape That Breaks the Surface
The defining feature of an open-top aquascape is hardscape that rises above the waterline. Driftwood branches arching upward, tall stone pillars, or a combination of both create a dramatic above-water silhouette. Spiderwood and horn wood are especially effective because their twisted branches look striking whether submerged or exposed.
Position the tallest hardscape element off-centre and at varying heights across the tank. The above-water portion should feel like a natural extension of the underwater scape — not a separate arrangement perched on top.
Emergent and Epiphytic Plants
Emergent plants — those that root underwater but send stems and leaves above the surface — are essential for an open-top layout. Excellent choices include:
Hygrophila pinnatifida. Grows both submerged and emersed, producing attractive lobed leaves above water. It attaches to driftwood and can drape naturally over the rim.
Bucephalandra. While typically submerged, Bucephalandra thrives emersed on driftwood that extends above the waterline, provided humidity stays high.
Anubias. Hardy enough to grow with roots in water and leaves in open air. The thick, waxy leaves resist drying out.
Terrestrial mosses and ferns. Small ferns and mosses can be placed on exposed wood above the waterline. Mist regularly or rely on Singapore’s ambient humidity to keep them hydrated.
Pothos and Spathiphyllum. Not strictly aquatic, but their roots grow beautifully in aquarium water while the leaves cascade above — a popular choice for paludariums and open-top setups alike.
Lighting an Open-Top Tank
Without a lid, pendant or clamp-mounted lights work best. ADA Solar RGB, Twinstar, Chihiros, and ONF are all popular among Singapore aquascapers. A pendant suspended 20–30 cm above the water’s surface provides even coverage and avoids heating the water. Clamp-on lights like the Chihiros WRGB II Slim attach to the tank rim and are easy to adjust.
Light spillage onto the emersed zone is a bonus — it feeds above-water plants and creates attractive reflections on the ceiling and walls, especially at night.
Managing Evaporation
Open-top tanks in Singapore can lose one to two centimetres of water per day, depending on room temperature and air-conditioning usage. Top up with RO or distilled water — not tap water — to avoid mineral accumulation. An auto top-off (ATO) system with a float valve and reservoir takes the manual effort out of this routine. Budget ATO kits from brands like Kamoer are available for SGD 40–80 on Shopee.
Mark the desired water level on the glass with a small piece of tape as a visual reminder if you prefer manual top-ups.
Fish-Proofing Without a Lid
Some fish jump. Surface dwellers like hatchetfish and certain killifish are notorious for leaping out of open tanks. Choose livestock carefully — rasboras, tetras, and bottom-dwellers like corydoras rarely jump. If you must keep potential jumpers, a clear acrylic mesh or net cover stretched across the top provides protection without ruining the aesthetic. Floating plants also deter jumping by reducing open water surface.
Maintenance Tips for Open-Top Setups
Clean mineral deposits (white crust) from the glass rim weekly with a damp cloth or a vinegar-soaked paper towel. Trim emersed growth to maintain the intended silhouette — open-top plants grow vigorously once established and can overwhelm the composition if neglected. Wipe down pendant light fixtures monthly to prevent dust buildup that reduces output.
The open-top aquascape is the ultimate expression of the planted-tank art form. It invites viewers to look not just into the water but above it, where the boundary between aquatic and terrestrial life dissolves. Visit Gensou Aquascaping at 5 Everton Park to see our open-top displays and find the perfect rimless tank for your home.
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5 Everton Park #01-34B, Singapore 080005 · Open daily 11am – 8pm
