Yes, C02 is needed for pearling to happen.turtlehead said:my riccia is not pearling like most of the pictures I've seen of it is it because I don't add co2? 3.8wpg 10g and is that too much lighting? I've been using excel and ferts
No, that is not to much light; however you do need to add C02. Excel is only a carbon source and will not have the same benifits as injected C02.