What are the optimal conditions? Mine are under med-high light, and the roots have always been red, but not high enough light to turn the leaves red. They have been without co2 for a few weeks now while waiting for a new regulator to come in. Are you sure its the roots and not just the leaves that change color under non-optimal conditions?
I have seen red root floaters with white roots and some with pink, not red, roots. Water nutrients seem to play a role in the root color variation. My guess would be the amount of iron. But I don't know what the optimal conditions are.
No. They all look like single leaves up to four leaf clovers.
The color of roots and leaves are often influenced by environmental factors like water nutrients and light intensity. They are therefore not very reliable for plant identification. But the anatomical (structural) features of plants are very stable across environments.
Since we know that red root floaters are populated through runners, when there is no runner and yet the plants keep populating themselves, we know that they cannot be red root floaters.
Taari - Not RRF
Firemedic269 - Not RRF
chris.rivera3 - That's RRF
mistahoo - Not frogbit. That's water lettuce
bluestems - I think you nailed what Taari has.
RRF propagates through runners, creating great big chains of RRF, not 4 leaf clusters. New leaves tend to curl up at the sides and overlap existing leaves, and with proper lighting you get little white flowers.