How to Clean Fish Tank Decorations Guide: Safe Methods

Decorations gather biofilm, algae and mulm whether they are ceramic skulls, plastic Buddhas or natural driftwood. Cleaning them badly kills the cycle; cleaning them well barely disturbs it. This how to clean fish tank decorations guide from Gensou Aquascaping at 5 Everton Park covers chemical-free methods that work in Singapore’s humid climate, where algae regrows faster than many first-time keepers expect. Get the technique right and you will rarely need to scrub the same piece twice in a month.

What Not to Use

No household soaps, dish detergents, bleach wipes or vinegar sprays unless you can guarantee full rinsing and complete air-drying. Even a trace of detergent lowers fish mucus protection. Vinegar at 5 percent works on calcium deposits but must be rinsed, neutralised with baking soda water, and rinsed again. In practice, physical cleaning with hot water and a brush handles 95 percent of jobs with zero chemistry risk.

The Bucket and Brush Method

Remove decorations during a regular water change. Place them in a bucket of old tank water — not tap water, because chlorine kills the useful bacterial film on the decoration. Scrub with an old toothbrush or a dedicated aquarium brush from Qian Hu (SGD 4). Ninety percent of algae lifts within two minutes. Rinse in more old tank water, then replace. The surviving biofilm re-seeds the cycle without issue.

Cleaning Plastic and Resin Ornaments

Cheap plastic tends to scratch, which creates algae hiding spots. A soft toothbrush and old tank water remove surface film; stubborn spots respond to a gentle thumbnail scrape. Resin ornaments are harder and tolerate firmer scrubbing. Watch for paint flaking on colourful pieces — if flakes appear, retire the decoration because leached paint pigment is unpredictable in low pH Singapore tap water.

Ceramic and Glazed Pieces

Glazed ceramic is the easiest to clean because the surface is sealed and algae cannot anchor well. A quick brush in old tank water restores them fully. Unglazed terracotta pots used for shrimp hides hold algae more stubbornly; a 10-minute soak in hot tap water (not boiling, because thermal shock cracks terracotta) followed by a scrub does the job. Rinse thoroughly before returning to the tank.

Natural Driftwood

Driftwood develops a biofilm that catfish and shrimp actively graze; leaving it alone is usually the right move. If it has become visibly smothered in hair algae, remove it, scrub with a coarse brush in old tank water, and consider a three-day blackout on the tank afterwards to prevent regrowth. Never bleach driftwood unless you are willing to soak it in dechlorinated water for a week to remove residual chlorine.

Rocks and Stone Features

Small rocks can be removed and scrubbed the same way. Large aquascape stones are better cleaned in place using a toothbrush held on a long plastic handle (zip-tie an old brush to a bamboo chopstick). Disturbing a mature aquascape to scrub one rock often releases more mulm than the algae was producing. Judgement call based on how bad the algae looks.

Biological Filter Media vs Decoration

The confusion worth clearing up: ceramic rings in filter baskets are biological media and must never be scrubbed aggressively. Decorative ceramics in the tank itself are different — they are for aesthetics and can be cleaned. If in doubt, rinse in old tank water only, never tap water, and the tank’s biology stays intact either way.

Dealing With Calcium Deposits

PUB tap water in Singapore is soft (GH 2-4), so calcium deposits on decorations are rare. When they do appear it is usually on tanks topped up heavily during dry spells when TDS concentrates through evaporation. A 5 percent white vinegar dip for 10 minutes dissolves deposits; rinse in tap water, then in old tank water, then return. Neutralise residual vinegar with a teaspoon of baking soda in a rinse bucket if you are cautious.

Frequency in Singapore Conditions

Warm year-round temperatures accelerate algae on decorations. Most tanks need a decoration clean every 4-6 weeks during water changes. If algae comes back within 10 days, the root cause is usually lighting duration (over 8 hours) or elevated nutrients, not the decoration itself. Treat the source, not the symptom; otherwise you will be scrubbing weekly.

Storing Spare Decorations

Pieces rotated out of a scape can be stored dry in the HDB laundry yard. A plastic Ikea box (SGD 5) keeps them organised. Allow them to air-dry fully before storage; Singapore humidity encourages mould on damp porous items. A quick rinse in old tank water when returning them into use revives any dormant biofilm.

Related Reading

• How to Clean Fish Tank Rocks Guide
• Driftwood Preparation Guide Singapore
• Aquarium Algae Control Guide
• Fish Tank Maintenance Tips Guide
• Aquarium Maintenance Schedule Singapore