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I've been trying to grow some red plants like Ludwigia and Alternanthera in my 20-gallon tank, but they keep turning green. I'm using a Finnex Planted+ light and dosing Thrive fertilizer weekly. Any tips to bring out the reds?

Red plants need high light and iron to maintain their color. Your Finnex light should be sufficient, but you might need to increase the photoperiod to 8-10 hours. Also, check your iron levels, as deficiencies can cause fading. I've had success with Seachem Iron supplements.

Yeah, Nebulon's spot on. I've got some Rotala H'ra that was looking kinda sad until I bumped up the iron. Now it's popping. Also, keep an eye on nitrates, too high and they'll mess with the colors.

My Ludwigia was doing the same thing until I switched to a richer substrate like ADA Amazonia. The extra nutrients made a huge diff. Also, CO2 helps if you're not already using it.

I've heard lowering nitrates can help, but I'm not sure how low to go. Anyone have experience with that?

taylord wrote: ↑Tue Jul 22, 2025 8:39 pm I've heard lowering nitrates can help, but I'm not sure how low to go. Anyone have experience with that?

Aim for 5-10 ppm nitrates. Too low can stunt growth, but keeping it in that range should help with coloration. I test weekly to stay on top of it.

Yo, my red plants were straight up ghosting me until I cranked the light. Now they're vibing. Also, dunlow8's right about CO2, it's a game-changer.

Thanks for the advice, everyone. I'll try increasing the iron and adjusting the light schedule. Appreciate the help!

stormy1 wrote: ↑Tue Jul 22, 2025 11:50 pm Thanks for the advice, everyone. I'll try increasing the iron and adjusting the light schedule. Appreciate the help!

No prob, dude. Let us know how it goes. Red plants can be finicky, but once you dial it in, they're worth the hassle.

Also, if you're not into CO2, try liquid carbon like Excel. It's not as good, but it'll do in a pinch.