Products marketed as liquid carbon are not actually liquid carbon. Karen Randall wrote quite an informative article about it here: The Myth of "Liquid CO2" and the Dangers of Glutaraldehyde - Redux — Sunken GardensI know it has a limited effect compared to a typical set up, but that’s outside my ability for several different reasons. I tried looking this up already but they were all results from before 2020 and I don’t know if it holds true anymore.
The only one I’ve used before was Flourish Excel, but I really hated the bottle so I’d prefer to try another one. I know about the API one and the one from Aquarium Co-op, but are there any others that are good?
Supposedly, such products are just glutaraldehyde. I think there are some folks that will buy straight glutaraldehyde but I wouldn't recommend it.
I think Excel is alright. What do you not like about the bottle?