Hi Teresa, welcome to my circle of friends. Here we shall have ample time to discuss problems with fish and plants in such an environment. As I said, i have some experience with fish and shall share what I know, which in the end is not much different from what I do already.
Fish have very similar build, have respiratory, digestive and excretion systems and reproduce sexually and thus the problems are similar too. Only the environment plays a separate role from other living entities like plants or are human and animal. With fish it is water, with plants it is soil and with the rest it is the space above ground and water.
So the homoeopathic laws always apply. Like produces like, like attracts like, like imitates like, like cures like and like neutralises like. You see this everywhere i nature and all five points equally apply. So these are the things you are on the lookout for in taking a case of sick anything - human, animal plant, fish, insect, whatever. If you always keep these 5 points in mind when watching a problem, the similarity principle - the Law of Similars - will always give you the easiest way out.
Welcome Teresa, I hope you enjoyed yourjourney with us. As you may well see, our mission is to heal the planet, one individual at a time by any means necessary. Currently we are discussing autism, what it is, where it came from, what causese it etc. Feel free to add any insights that you may have.