FAQ: Plants for fish

Hornwort has no true roots, so it can be left floating or lightly pushed into the substrate. It grows very fast, absorbs nitrates well and even suits cool water, but it may shed needles when conditions change.

Cabomba is a lovely fine-leaved stem plant, but it needs fairly strong light, softer water and fertiliser. Under weak light it quickly grows leggy and drops leaves, so hornwort suits an undemanding tank better.

Elodea is a fast-growing, undemanding stem plant that also suits coldwater tanks. Trim it regularly and replant the tops; in a warm tropical tank it may grow less well than in cooler water.

The red tiger lotus grows from a bulb and produces large red leaves, sometimes floating ones too. If you want it to stay underwater, cut off the floating leaves, and push a root tab in near the bulb.

Monte Carlo and similar carpeting plants grow best under strong light, with CO2 and a fine nutrient-rich substrate. Plant them in small clumps, trim them short regularly and keep the water clean with frequent changes at first.

Hairgrass spreads by runners and forms a grassy lawn in the foreground. Plant it in small clumps leaving gaps for runners, and trim an overgrown lawn now and then so the lower parts do not rot.

Ludwigias are stem plants that range from green to deep red depending on light and iron. They are fairly undemanding, but the strongest colour comes out under strong light with micronutrient fertiliser.

Rotalas are fine-leaved stem plants suited to the background. They grow fast, like strong light and regular trimming, and the tops of some species turn red under intense lighting and CO2.

Hygrophilas are among the least demanding stem plants, growing fast and soaking up nutrients well. Trim them regularly and replant the tops, and if leaves yellow or develop holes, add fertiliser.

Sagittaria are undemanding rosette plants that spread by runners and suit the foreground or midground. Moderate light and root tabs are enough, and dense patches can be thinned by cutting off runners.

Aponogetons grow from a bulb and produce long wavy leaves, so they suit the background. Some species go dormant after a few months of growth and drop their leaves, after which the bulb sprouts again.

Water lettuce needs a calm surface, an air gap under the lid and light, but must not touch a hot light fitting. Its long roots absorb lots of nitrate and shelter fry, and surplus plants should be removed regularly.

Most aquarium plants are propagated vegetatively, so seeds are rarely used. Aquarium plant seeds that are sold are usually grown in moist substrate before the tank is filled, but results vary and do not always match the picture.

Fast stem plants root within a few days to a week, rosette plants within a few weeks, and epiphytes take a month or more to grip rocks. During that time disturb the plants as little as possible.

Cyanoacrylate (superglue) gel is commonly used to attach plants, and once cured it does not harm the water. Use only a little, on the rhizome or roots rather than the leaves, and let it set before submerging.

It depends on the tank volume and how often you dose: the dose is usually given in millilitres per so many litres. Work out your weekly use, compare packs by price per litre, and store opened fertiliser somewhere cool and dark.

Zookainos.lt compares prices from Lithuanian online pet shops, and liquid fertiliser prices are easy to compare by price per litre. The site itself sells nothing: once you pick an offer, you buy it on the shop’s own site.

Prices are collected about daily, and each product shows when its price was last checked. Before buying, confirm the final price and availability on the shop’s own site.

Yes, product pages show price history, so you can see how the price of a fertiliser, substrate or light has changed. That helps you judge whether the current price is usual or worth waiting on.

Aquarium substrate comes in bags of various sizes, so comparing price per kilogram or litre is easiest. On zoogidas.lt products can be compared by price per kilogram or litre; work out the amount you need from the base area and layer depth.