Does anyone else find that houseplants make great aquarium plants?
My grandmother has an enormous pothos vine growing in her kitchen. Whenever it gets too long she cuts a few of the vines off and sticks them in a jar, where they root. Sometimes the cuttings stay in the jar for two years or more before she gets around to planting them, at which time they've grown very, very long. I figured that if they grow that well in a dark, stagnant jar of water on top of the refrigerator, they would do great in a fish tank full of nutrients with good lighting.
So I took some of the cuttings and stuck them in my open-topped ten gallon betta tank, which receives no artificial light, only light from an east-facing window, and no ferts except fish waste. I made sure a few leaves and the growing tips were out of water but half of the leaves were submerged. They seem to be the perfect aquarium plant - they grow very quickly and send down lots of finely branched roots at every node, which grow down to the substrate, providing cover for the fish. They also keep nitrates almost nonexistent. The plant even grows different smaller, thinner leaves if the growing tips fall underwater and this tip can then be cut off and planted in the substrate, where it grows new leaves in submersed form just as quickly, but stays much more compact and resembles a yellow variegated anubias.
Then there's sweet potato vine, an ornamental available at garden shops in the spring. It's a cultivated variety of the edible vegetable but it comes in pretty colors. We had some yellow ones growing in a flowerbox outside, and on a whim took a few slips and stuck them in the tank as well. They started growing roots within six hours, and in a week the roots were a foot long. After a month the plants were enormous, three feet long and sprawling across the table (were six inches when planted) with roots just as long and I took cuttings of them and started over, throwing out the massive roots systems because although the fish loved it, it was kind of excessive. I think this plant would be great in a large open-topped tank, but in my small one it needs restarting regularly to keep it in check. Also with this one the leaves have to stay above water or they rot. The new cuttings, replanted yesterday morning, have one inch roots already at the nodes.
And then there's creeping jenny, a golden groundcover plant sold for outside. I took some little cuttings from the garden and stuck them underwater in my shrimp tank. They rooted quickly and are growing very tall now. The submersed leaves look the same as the leaves grown on land but the plant grows upright instead of creeping along the ground.
I also planted some spider plant offshoots in my HOB filters, and they've sent down long roots into the tank as well and are growing nicely, and I'm trying Swedish ivy and philodendron in my tanks as well but they've yet to root.
Has anyone else had success with non-aquatic plants growing in an aquarium?