How to Grow Moss on Aquarium Decor
Moss turns plain decor into something that looks years old. It needs no soil and no special fertiliser, and Java moss in particular is very forgiving.
Quick answer
Rinse the moss, spread a thin layer over the decor, tie it on with cotton thread, and place it in gentle flow and moderate light. Trim it as it grows. Thin is the key, because moss buried in a thick clump turns brown.
Which moss to choose
- Java moss: the easiest. It handles a wide range of water and light, which makes it the best first moss.
- Christmas moss: a neater, fuller shape, but slower and fussier.
- Flame moss: grows upward in twists. Lovely, but give it time.
Mosses grow more slowly in very warm water, so in a hot room keep the tank out of the sun and give it good water movement.
How to attach it
- Rinse it. Wash the moss in a bowl of tank water and pick out debris and snails.
- Spread it thin. Tease it into a layer you can nearly see through.
- Tie it on. Wrap it with cotton thread or fine fishing line. Cotton slowly rots away after the moss has gripped. Aquarium-safe gel super glue also works on hard surfaces. Use a dot, and let it set before the piece goes back into water.
- Place it. Pick a spot with gentle flow, away from strong direct light.
- Wait. It can take a few weeks to attach, and you will see new bright green growth first.
Keeping it healthy
- Light: moderate is plenty. Very strong light mostly feeds algae.
- Flow: gentle movement stops dirt settling inside the moss.
- Cleaning: shrimp pick moss clean. Without them, swish it gently during water changes.
- Trimming: cut it back with scissors and net the cuttings, because loose bits drift into your filter.
Fixing common problems
Brown moss usually means the layer is too thick or too dirty. Thin it out and rinse it. Algae in the moss usually means too much light or too much feeding. Shorten the light hours and feed less.
Want a piece that is made for moss? Our Dancing Skeleton doubles as a moss planter, with bubbles rising through his ribcage.