Hey, basslover. I think there would be little or no PITA with weeds on a Biohaven Floating Island, as they are made out of recycled plastic. If it isn't planted deliberately, it doesn't have much chance to grow.
In reality, this is not true at all. I have lots of experience with floating islands from my last job....they require weeding several times per year; except you can't just pull them out unless they have just germinated because the roots end up growing through the island itself.
Cattails, willows, and cottonwoods seem especially fond of the plastic matrix and constant water supply!
There is a reason we find aquatic plants in the water, and terrestrial plants on land...those habitats provide the plant with it's requirements for growth and reproduction. As someone else mentioned, a typical fish pond does not have enough nutrients for most terrestrial plants and almost all vegetables to grow. It's not just NPK, there is also a requirement for calcium, sulfur, magnesium, and a handful of micro-nutrients/minerals....all in the correct balance (to avoid nutrient uptake competition), otherwise the plant will suffer in growth, health, and production. (and they use/need these nutrients at different rates at different growth stages)
Some plants like lettuces and herbs may do ok in a pond, but not as well as they would in the ground.
I hope that helps answer your questions.
