I have a 60L tank with plants for three months now and they're gradually turning yellow. I see tons of people using CO2 systems, but that's expensive and complicated. Are there plants that are easier and can survive without it?
Yellowing often comes from nutrient deficiency rather than CO2 - are you dosing liquid fertilizer regularly? Otherwise, with just proper lighting (8-10 hours a day) and good fertilizer, plants like anubias, java moss, or dwarf echinodorus do just fine without a CO2 system, you just can't expect crazy fast growth.
You don't need CO2 for aquarium plants, it's a huge marketing scam. Your problem probably isn't the lack of CO2 but rather a combination of several small things that are easy and cheap to fix. Yellowing rarely comes from CO2 alone - it's usually a nutrient deficiency, insufficient light, or bad lighting that doesn't give the right wavelengths.
Start with the basics: how many hours of light per day does your tank get? Because if it's less than 8-10 hours, your plants are going to struggle. Next, add a complete liquid fertilizer (not just nitrogen, you need iron, potassium, magnesium). That costs around 10-15€ for three or four months of use. There are also plants that survive just fine without CO2 - mosses, anubias, cryptocorynes, vallisneria. That stuff grows even when you do zero effort. If you want something more colorful, rotala and ludwigia tolerate the lack of CO2 well too, just with good LED lighting and fertilizer.
Try that first for two or three weeks before thinking about investing in CO2. Don't change everything at once, just add the fertilizer regularly and increase your light duration if it's low. Your plants should bounce back - if it doesn't work, we can dig into other problems like pH or temperature.
Log into answer.
