I have any old hot tub that we no longer use that I want to convert into a fish pond. Would like things to look somewhat finished and not just a utilitarian out do it tank. This would be a potential overwintering / hospital pond in the future but my main pond for now until I get my larger yard pond completed. I am looking for advise from someone who may have already completed such a conversion. Some highlights to include in your comments: best way to implement pump and filter into design. Best type of filter for this project, ideas on keeping things low maintenance. In design such as easy water changes. Did you use the fiberglass liner as is or place a pond liner inside? Is there a clever way to use the plumbing already there to perform/enhance the needed functions of the pond? Best way to cap off jets? Ways to add surfaces that will hold / grow beneficial bacteria and plants. Bare bottom or gravel? Warnings about pitfalls to avoid. Pictures would be appreciated.