The ditch moss (a moss found by a CKA member in a cattle watering trough which is so tough it will survive freezing in a Northern Illinois winter and come back strong next spring) is holding it's own. With the increased indirect light as summer comes on, the water lettuce are doubling their size.

Amazingly the Salvinia are turning brown and dying! As near as I can tell, the Water lettuce is sucking so many nutrients out of the tank that few other plants can compete! The fish are doing fine!

I knew that water hyacinth is a terrifically heavy feeder. Unfortunately it needs quite a bit of light and is something of a challenge to over winter indoors. Evidentally water lettuce falls into the same category. It will shrink, but not die off like the hyacinth.

When heavy feeders such as the water lettuce, water hyacinth, Salvinia and - oh yes - Amazon sword plants don't have enough food and light, they will dwarf. That is why I don't bother with sword plants anymore.

The moral of the story? Not all plants are compatible. Some will out compete the others. If that happens to you, don't go on a guilt trip - over that anyway. :)

There is even chemical warfare between plants. Chemicals are produced which inhibit the growth of other plants - including algae and even duckweed. Diana Walstad's Ecology of the Planted Aquarium spends some time on the phenomena of allelopathy, where some plants actually produce allelochemicals which can inhibit or even eliminate competing plant species.

That is why one seldom finds Val and Saggitaria side by side or water sprite and water wisteria (another Hygro) together. Ah there is so much to learn!