FAQ: Tank Decor for fish

Scrape snail egg clusters off decor and glass with a plastic scraper or an old card. If there are too many snails, feed less, as their numbers mostly depend on how much leftover food there is.

Blue-green algae form a slimy blue-green film with an unpleasant smell. Siphon it off, clean the decor, improve the flow, cut back the light period and feeding, and change water regularly.

Not always: decorative garden pebbles are often limy, marble or painted and are not meant for permanent immersion. If you use them, test them with vinegar and rinse them thoroughly, and leave out painted ones.

Shrimp do well on a dark, fine substrate: sensitive soft-water shrimp are often kept on a pH-lowering nutrient soil, while hardy shrimp are fine on inert sand or fine gravel. Avoid substrate with metal impurities.

Substrate heating cables are laid on the bottom under the substrate so warm water slowly circulates through the root zone. They are not essential, but some keepers use them for plants; choose sealed cables made for aquariums and follow the fitting instructions.

Gravel can turn green or brown from algae and diatoms, darken from tannins or organic deposits, and painted gravel can fade. Regular siphoning and dealing with the causes of algae usually help.

Scoop the substrate out with a plastic cup or container once the water level is lowered, or siphon sand into a bucket with a wide siphon. Do not use a metal scoop or sharp objects, so you do not scratch the glass or silicone seams.

Old gravel or sand can be rinsed, dried and reused, and spent nutrient soil makes a good addition to garden or houseplant soil. Do not dump substrate or tank water into natural waters.

Yes, a handful of substrate or a decoration from a healthy, running tank carries beneficial bacteria and speeds up a new tank’s cycling. The old tank must be free of disease, and you should still test the new tank’s water.

Themed decorations such as castles, ships or cartoon figures are fine if they are made for aquariums and have no sharp edges or narrow openings. Add natural hides or plants alongside them so the fish feel secure.

Yes, many fish rest among plants, under roots or in caves at night, while nocturnal fish hide during the day. Enough hides and a dark night without extra light help fish keep a natural rhythm.

In a tank viewed from several sides, put the tallest decor in the centre or on a diagonal with lower pieces around it, so it looks interesting from every angle. Hide the equipment under decor or in one corner, and leave hides for the fish.

It is not advisable, because many minerals contain metals such as copper or iron compounds, or dissolve in water. If you want a decorative stone, choose quartz or other rocks known to be inert, and test them with vinegar.

New resin or plastic decor only needs a good rinse in warm water without detergent to wash off manufacturing dust. If a piece smells of chemicals, soak it for a day or two with water changes, and do not use one that keeps a strong smell.

Cloudiness is usually unrinsed dust or disturbed substrate, while foam can come from detergent residue or substances leaching out. Take the decoration out, rinse it thoroughly, change some water and watch the fish.

Many freshwater crabs need not just water but a land area with rocks or roots they can climb out on. Crabs are excellent climbers, so decor must not reach the lid and the tank must be tightly covered.

Driftwood lowers pH and hardness slightly, and Malawi and Tanganyika cichlids need hard, alkaline water, so their tanks mostly use rock. A small piece of wood in hard water has little effect, but it is worth watching the parameters.

Yes, anubias, Java fern and mosses can be tied or glued to resin or ceramic decor, and over time they grip with their roots. This makes an artificial decoration look more natural and less prone to algae.

New fish often hide until they settle in, while long-term hiding can point to stress from aggressive tankmates, light that is too bright, a group that is too small or poor water quality. Check the water parameters and how well the fish suit each other.

Fish occasionally rub themselves naturally, but frequent rubbing against rocks, substrate or decor can point to parasites, skin irritation or poor water quality. Check the water parameters, and if the rubbing continues, contact a vet.