Guys... this sounds silly, but can you put juvie goldfish in planted tanks and move them to an indoor pond before they get too destructive with your plants?
How small should I get the goldfish? And what are some goldfish safe plants? These are some plants that are goldfish safe? THese are the plants I have in my planted tank. Echi Red Diamond, Echi Red Special, Echi Indian Red, Tiger Lotus, Mini Java Fern, Java Moss, Anubias Nana, Staurogyne Repens, Java Fern 'Thors Hammer alias Giant Windelov'
My observation is by no means scientific, but I remember that my Ryukin gold fish were incredibly aggressive towards plants.
When I bought my Ranchu goldfish, he left my Anubias alone. I don't know whether it has to do with their history of feeding, but I'm sure glad my Rachu is able to live in a planted tank.