Use cleaning tools made for your tank’s material: glass tools on acrylic will scratch it. Check magnets and pads for sand before every use, because one grain dragged across the glass leaves a scratch. Clean little and often, use a scraper for stubborn spots, and polish the outside with a dry microfibre cloth.
Glass or acrylic?
Reef Builders’ first rule is to use only tools intended for your surface. Acrylic is much softer: glass-cleaning kit can scratch it quickly. Scrapers often come with a plastic blade for acrylic and a metal one for glass, and magnets come in glass-safe and acrylic-safe versions.
Avoiding scratches
Sand is the main danger. Reef Builders advises checking the pad and both magnets for grit before use, and taking care not to pick up sand while cleaning, especially near the bottom edge. Carry the pad in and out face up so it doesn’t collect debris.
If the magnet falls off and lands in the sand, rinse it before using it again.
Stubborn spots
Coralline algae and tough film need a scraper. On glass, a metal blade held flat works well; keep it away from silicone seams. On acrylic, use only a plastic blade.
The outside
Reef Builders suggests a cotton towel for drips and dust and a microfibre cloth for polishing. Wipe off salt creep before it builds up. Use only cleaners that are safe near aquariums; household sprays can contain chemicals you don’t want near the water.
How often
Reef Builders says to repeat as often as algae returns. For most tanks that’s every few days for the front glass. Cleaning before the film gets thick takes a minute, not twenty.
Common questions
How do I remove scratches from aquarium glass?
Light scratches on acrylic can often be polished out with a kit. Glass is much harder; prevention is the answer.
Can I use a razor blade on my tank?
On glass, held flat and away from the silicone. Never on acrylic.
What can I clean the outside glass with?
A damp cloth, then a dry microfibre. Avoid household sprays near the tank.
Sources and limits
Last checked 13 October 2026. Follow your equipment maker’s own instructions where they differ from this guide.
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