Who Gives A Fish Forums

My Anubias and Java Fern have been looking dull lately. The leaves are pale, and some have brown spots. I've got a 20-gallon tank with LED lighting, CO2 injection, and I dose liquid ferts weekly. Water params are good, 0 ammonia, 0 nitrite, 10 nitrate. What's going on?

Sounds like a light or nutrient issue. How long are your lights on each day? Too much light can bleach plants, but too little and they won't thrive. Also, what's your phosphate level? Low phosphate can cause those brown spots.

I had the same problem with my Crypts. Turned out my light was too intense. Dialed it back to 6 hours a day and they perked up. Maybe try adjusting your photoperiod?

Yo, check your CO2 levels too. If they're all over the place, plants get stressed. My tank was a mess till I got a drop checker. Now everything's chill.

axonix wrote: ↑Sun Sep 07, 2025 4:39 pm Sounds like a light or nutrient issue. How long are your lights on each day? Too much light can bleach plants, but too little and they won't thrive. Also, what's your phosphate level? Low phosphate can cause those brown spots.

Lights are on for 8 hours. I haven't checked phosphate, though. Gonna grab a test kit tomorrow.

Could be a micronutrient deficiency. Are you using a comprehensive fertilizer? Some just focus on macros and skip the trace elements plants need.

My plants looked sad till I switched to root tabs. Maybe your substrate's tapped out? Just a thought.

Have you considered the age of your bulbs? LED or not, they lose intensity over time. Replacing mine made a huge difference.

Wavytide wrote: ↑Mon Sep 08, 2025 12:19 pm Yo, check your CO2 levels too. If they're all over the place, plants get stressed. My tank was a mess till I got a drop checker. Now everything's chill.

Second this. CO2 stability is key. Also, what's your KH? If it's too low, pH swings can mess with uptake.

duskfly wrote: ↑Mon Sep 08, 2025 2:09 pm

axonix wrote: ↑Sun Sep 07, 2025 4:39 pm Sounds like a light or nutrient issue. How long are your lights on each day? Too much light can bleach plants, but too little and they won't thrive. Also, what's your phosphate level? Low phosphate can cause those brown spots.

Lights are on for 8 hours. I haven't checked phosphate, though. Gonna grab a test kit tomorrow.

Good call. Phosphate is often overlooked. If it's low, a little monopotassium phosphate can fix it fast. Just don't overdo it.