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My Anubias roots are turning black and I'm not sure why. The tank is a 20 gallon with Fluval Stratum substrate, LED lighting for 8 hours a day, and a sponge filter. Water params are good, 0 ammonia, 0 nitrite, 10 nitrate. I dose Seachem Flourish once a week. Any ideas?

Could be a nutrient deficiency or maybe too much light. I had a similar issue with my Java Fern when I cranked up the light too high. What's your lighting setup like?

lorixa wrote: ↑Sat Jun 28, 2025 8:14 pm Could be a nutrient deficiency or maybe too much light. I had a similar issue with my Java Fern when I cranked up the light too high. What's your lighting setup like?

I agree with lorixa. Also, how often are you doing water changes? Stratum can leach nutrients over time, so regular changes might help.

Black roots can also indicate rot from poor water flow or stagnant conditions. How's your filter flow? Anubias prefer a bit of movement around their roots.

I've seen this happen when the roots are buried too deep in the substrate. Anubias rhizomes should be above the substrate, just like Java Fern. Are yours planted or tied to something?

Yo, sounds like your roots are straight up chillin' in bad conditions. Check if they're mushy. If they are, it's rot for sure. Trim the black parts and glue the healthy bits to a rock or driftwood.

Black roots in Anubias are often a sign of anaerobic conditions in the substrate. Fluval Stratum is nutrient-rich but can compact over time, reducing oxygen flow. Try stirring the substrate gently during water changes or consider adding root tabs to boost nutrient availability.

I'm so sorry you're dealing with this! It's frustrating when plants don't thrive. Have you checked the roots for any signs of pests or algae? Sometimes black roots can be a secondary symptom of another issue.

Thanks for all the advice, everyone. I'll try lifting the rhizomes out of the substrate and adjusting the light. Appreciate the help!

No prob! Let us know how it goes. Also, if you're dosing Flourish, maybe try adding some Iron. Anubias can be picky about trace elements.