Who Gives A Fish Forums

My Java Moss has been turning brown lately, and I can't figure out why. The tank is a 20 gallon with moderate lighting, CO2 injection, and weekly water changes. Parameters are 0 ammonia, 0 nitrite, 10 nitrate. Any ideas?

Brown moss usually points to lighting or nutrient issues. How long are your lights on each day? Also, what's your fertilizer routine? Too much light without enough nutrients can cause browning.

Mine did the same thing last month! I cut back the light to 6 hours and added some liquid ferts. It's kinda chill now, but still sketchy in spots. Maybe try that?

zena4x wrote: ↑Fri Jul 04, 2025 7:36 pm Mine did the same thing last month! I cut back the light to 6 hours and added some liquid ferts. It's kinda chill now, but still sketchy in spots. Maybe try that?

Reducing light is a good start, but make sure your CO2 levels are stable too. Fluctuations can stress moss. What's your drop checker showing?

Thanks for the tips. Lights are on for 8 hours, and I dose Thrive twice a week. Drop checker is lime green, so CO2 seems fine. I'll try cutting the light to 6 hours and see what happens.

Could be algae competing with the moss. Have you checked for any hair algae or biofilm? Sometimes moss gets smothered. A quick trim and a clean-up crew might help.

I had a similar issue in my 10 gallon. Turned out the flow was too low, and debris was building up. Added a small powerhead, and the moss perked right up. Maybe check your flow?

Yo, moss is weird like that. Mine went brown when I switched to a new fert brand. Switched back, and it was all good. Maybe your Thrive is off?

Moss can be finicky with water changes too. If you're doing big changes, it might shock the plant. Try smaller, more frequent changes and see if that helps.

Hawaiiano wrote: ↑Sat Jul 05, 2025 1:00 am Moss can be finicky with water changes too. If you're doing big changes, it might shock the plant. Try smaller, more frequent changes and see if that helps.

That's a good point. Stability is key with moss. Also, make sure your water changes match the tank's temp to avoid further stress.