Plant fertilizers

I?m fairly new to freshwater plants in aquariums and have done some
research on plant fertilizers and supplements.  I?ve been taken back
by the different types and recommendations.  Can someone give me some
simple advice on what I need to do to and add to my tank to maintain
and promote plant growth and health?  What products work well and are
easy to use?  What about CO2 injection?

Thank you
Fred
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