Quick wipes
One half sits inside, one outside. Match it to your tank material and glass thickness.
- Floating inner halves are easier to retrieve
- A magnet that is too strong is hard to steer
- Keep fingers clear as the halves snap together
Routine care
Glass Cleaning and Algae Scraping
A clear view takes a few minutes and the right tool for your tank. Learn how to use magnets, scrapers and pads without scratching, why to clean before a water change, and what fast regrowth is telling you.
Know your tank
Glass or acrylic?
Check this before you buy a cleaner. Glass tanks usually have silicone seams in the corners. Acrylic tanks usually have seamless corners and often a solid top with cut-outs.
Check the label or manual if you still have it. If you are not sure, treat the tank as acrylic until you know.
- Glass: magnets, pads and metal blades are all fine. Keep blades off the silicone seams.
- Acrylic: use only magnets and pads labeled acrylic-safe. No metal blades and no abrasive scrub pads; use plastic blades for tough spots.
- Both: sand or gravel caught under a pad can scratch. Acrylic scratches very easily, and hard sand can mark glass too.
- Both: keep aquarium tools separate, with no soap or household cleaners.
What you need
Pick the right tool
Most tanks need a magnet for quick wipes and a scraper for the spots it cannot shift.
Blades for tough spots
A long-handled scraper reaches the bottom without your arm in the water.
- Metal blades on glass only
- Plastic blades for acrylic
- Replace dull, chipped or rusty blades
Aquarium-only pads
Use pads made for aquariums and labeled for your tank material.
- No kitchen sponges or scrubbers
- Rinse before and after use
- Store them with your aquarium tools
Damp microfiber cloth
Water and a clean cloth handle most smudges, drips and salt spray on the outside.
- No household sprays near the tank
- If you use a cleaner, spray the cloth away from the tank
- Dry with a clean towel
Step by step
Do these in order
Light, regular cleaning is easier on the tank and the glass than a hard scrub once a month.
Clean before a water change
Loosened algae then gets siphoned out or caught by the filter instead of settling back.
- Do the glass first, then siphon
- Give debris a few minutes to settle
- Rinse or swap filter socks afterward
Keep sand out
One trapped grain can drag a long scratch across the panel.
- Rinse the pad or magnet before you start
- Stop the magnet above the sand line
- If it drops, lift it out by hand and rinse it
Use light strokes
Steady, overlapping passes work better than pressing hard.
- Hold blades at a shallow angle
- Stay off silicone seams and trim
- Use the scraper, not the magnet, along the sand
Finish outside
Wrap up away from the water and look after your tools.
- Wipe the outside with a damp cloth
- Rinse tools in fresh water and let them dry
- Watch for drips near cords and outlets
Read the glass
What fast regrowth means
A little film every few days is normal. If the glass is green again in a day or two, the tank is telling you something.
Back in a day or two
Usually too much light, too many nutrients, or both.
- Check how long the lights run
- Keep direct sunlight off the tank
- Test nitrate and phosphate; feed less
Wipes off easily
Brown diatom film is common in new tanks and usually fades as the tank matures.
- Keep up with water changes
- Silicate in source water can feed it
- Wipe it off and be patient
Peels off in sheets
Slimy sheets are often cyanobacteria, not true algae. Scraping alone will not fix it.
- Look for weak flow and dead spots
- Test nitrate and phosphate
- See the cyanobacteria guide
Will not wipe off
Hard green spots and pink or purple coralline algae need a blade.
- Metal blade on glass only
- Plastic blade and patience on acrylic
- Coralline on reef glass is normal
Common mistakes
Avoid scratches and residue
Most scratches come from sand, the wrong blade or too much pressure. Most chemical problems come from household products that drift into the water.
- Metal blades or scouring pads on acrylic. They scratch on the first pass.
- Dragging a dropped magnet back up. It picks up sand. Lift it out and rinse it.
- Spraying cleaner near the tank. Overspray and fumes can reach the water. Ammonia-based glass cleaners are a real risk to fish.
- Kitchen sponges or soapy buckets. Leftover residue can harm livestock.
- Scraping into silicone seams. A blade can cut the seal.
- Scraping harder instead of finding the cause. Fast regrowth points to light or nutrients.