I did have some Parrot's Feather in there over the winter to help keep the water cleaner & it grew like crazy. Pulled it out as soon as I saw it was getting too big. Luckily it hadn't rooted itself too much into the pots. The King Tut papyrus did go crazy too & it was a monster when I pulled it out today. Having a mild winter also helped. The biggest drawback are the covered ponds not getting any rain to help freshen the water. One year I forgot to check the water level & it was down a lot. Had to run water to the pond from my Python aquarium hose to top off before the deep freeze set in. Hope your making a GH prevented your loosing any tropicals.