Who Gives A Fish Forums

My Anubias leaves are turning yellow, and I'm not sure if it's a nutrient issue. I've got a 20 gallon tank with moderate lighting, CO2 injection, and I dose Seachem Flourish twice a week. Any ideas what's missing?

Yo, sounds like you might be low on iron, fam. Check if the veins stay green while the rest yellows. That's classic iron deficiency. Try adding some iron supplement, like Flourish Iron, and see if it helps.

Nah, it's prolly nitrogen. Yellow leaves usually mean nitrogen deficiency, especially if it's the older leaves. You dosing any nitrate? If not, grab some and see if it perks up.

Could be potassium too. I've had similar issues in my 40 gallon. Started dosing potassium and the yellowing stopped. What's your water change schedule? Frequent changes can strip nutrients.

I'm new to this, but my plants were yellowing and someone told me to check the pH. Turns out mine was too high. Maybe test your water?

Sivaso wrote: ↑Thu May 08, 2025 12:30 am Yo, sounds like you might be low on iron, fam. Check if the veins stay green while the rest yellows. That's classic iron deficiency. Try adding some iron supplement, like Flourish Iron, and see if it helps.

I agree with Sivaso. Iron deficiency is common with Anubias. I'd also check your lighting. Too much light can stress plants and make deficiencies worse.

I've had success with a balanced fertilizer like Thrive. It covers all the bases, so you don't have to guess. How long have you had the Anubias? Sometimes they just take time to adjust.

Yo, don't forget about magnesium. Yellow leaves with green veins can also mean magnesium deficiency. Epsom salt is a cheap fix. Just dissolve a bit in water and dose it.

Test your water parameters first. Without knowing your nitrate, phosphate, and potassium levels, it's hard to say. Get a good test kit before you start dumping stuff in.

I've been keeping plants for years, and yellowing is usually nitrogen or iron. But like jensen8 said, test your water first. No point guessing when you can know for sure.