Moss, Anubias, Java fern and Bucephalandra are epiphytes: in the wild they anchor to wood and stone rather than rooting in soil, and their roots are for gripping, not feeding. Your job is simply to hold them against the surface, still and in contact, until those roots take over. How you hold them depends on the size of the piece and whether you are working wet or dry.
Tying Moss So It Grows In, Not Out
Pull Java moss apart and spread it in a layer far thinner than feels sufficient, because moss piled thick rots in the middle where light and flow cannot reach. Lay the strands along the branch or stone, following its line, then wrap dark cotton thread around and around in a loose criss-cross to pin it down. Cotton is the beginner's friend because it slowly dissolves over the following weeks, by which time the moss has attached itself, so there is nothing to cut away later. Fishing line lasts longer for awkward pieces on smooth rock, but remember it stays there and will need snipping out once the moss is established.
Gel Glue for Rhizome Plants and Small Pieces
For Anubias, Java fern and small moss tufts in hard-to-tie corners, gel superglue is the quickest hold. Lift the wood or rock out, dab the contact patch dry with a paper towel, put a small blob of gel on the rhizome or the underside of the moss, and press it to the surface for half a minute. The gel sets on contact with water, so mist the piece, return it to the tank, and the bond is done. Work in small dabs: a big squeeze turns white and crusty underwater and can smother the very roots you are trying to encourage.
The One Rule That Matters: Rhizomes Stay Exposed
Every epiphyte with a rhizome — that thick green stem running sideways, with leaves rising from one side and roots dangling from the other — must sit with the rhizome itself in open water. Bury it in substrate, wedge it into a crack, or smother it in glue and it blackens and rots, taking the plant with it. Roots may wander into a crevice and grip there, which is exactly what you want; the stem itself needs flow around it. When tying a fern to a stone, loop the thread around the stone and under the rhizome so the stem rests on top, visible from the front.
Settling In: Light, Flow and the Waiting Weeks
Newly attached epiphytes grow slowly, and their broad leaves are prime seating for algae while they adjust, so give them moderate light rather than the brightest spot in the tank and a gentle current that keeps debris from settling on the leaves. Expect moss to look scruffy for the first few weeks, then push out bright new tips once it has gripped. Snip any thread that works loose before fish investigate it, and trim moss back in small snips so the underlayer keeps getting light.
Because the follow-up jobs stretch over weeks — checking threads, trimming the first straggly growth, moving a piece that is sulking in too much light — it helps to share them out rather than rely on memory. Listing moss care as small recurring duties on the tank's Care Teams rota in KinsLe means whoever feeds the fish that week also knows which branch needs a look, and each finished check is ticked off with a timestamp.