Liquid carbon for aquatic plants is typically used as an alternative to CO2 gas injection in planted aquariums. It provides a readily available source of carbon, which is essential for photosynthesis and healthy plant growth. Here are some key points about using liquid carbon in aquariums:

1. Forms and Application:

   - Liquid carbon products usually contain glutaraldehyde or a similar compound, which breaks down in water to release carbon.

   - It's added directly to the aquarium water, often on a daily basis, according to the dosage instructions on the product.

2. Benefits:

   - Helps enhance plant growth and vitality.

   - Can suppress the growth of algae by providing plants with a competitive advantage.

   - Easier to use compared to CO2 gas systems, which require more equipment and maintenance.

3. Considerations:

   - Overdosing can harm sensitive plants, fish, and invertebrates.

   - It's important to follow the manufacturer's dosage recommendations carefully.

   - It might not be as effective as CO2 gas injection for heavily planted or high-light aquariums, which have higher carbon demands.

4. Popular Products:

   - Seachem Flourish Excel

   - Easy Life EasyCarbo

   - API CO2 Booster

Using liquid carbon can be an effective way to boost plant growth in an aquarium, especially for hobbyists looking for a simpler method than CO2 gas injection.