Green spots only on my anubias leaves even at six hours of light

Question

Hard little green dots that will not wipe off, and they are exclusively on the anubias, the crypts and the java fern next to them are clean. I already cut the…

burr_and_bloom · Accepted Answer

Green spot algae, and the counterintuitive fix is phosphate. Low phosphate in the water column is what triggers it, so dosing rather than starving is the move. I add enough of a comprehensive fertiliser to keep phosphate somewhere around 1ppm and the spots stopped appearing on new leaves within a month.

It showing up only on anubias makes sense too. Slow growing plants hold each leaf for a year, so anything that lands on them stays. Fast growers just outgrow it.

krausen_line · Answer

Also check where the anubias is sitting. Mine was directly under the middle of the light and the same species tucked in shade three inches away was spotless. Anubias is a shade plant, putting it under driftwood or a taller stem solves a lot without touching the photoperiod.

coldsoak_kim · Answer

Existing spots will not go away on their own, the leaf is scarred. Nerite snails are the only thing I have found that genuinely rasps it off, and they will spend days on a single anubias leaf. Otherwise scrape gently with a fingernail on the older leaves and accept the worst leaves stay ugly until you trim them.

tuckplanche_theo · Answer

Cutting light hours mostly does not fix green spot, which matches what you saw. Intensity and nutrient balance matter far more than duration for this one specifically.

Green spots only on my anubias leaves even at six hours of light Algae

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