Ranalisma rostrata – In a Different Light

I’ve been growing Ranalisma rostrata in my 40G tank as the foreground for some time. When I originally setup my 20H, I decided to also plant it in there. As the 20H progressed, I realized that I had too much light, too little CO2, and too little desire to maintain the tank as I really wanted. Therefore, I removed the 55W PC light from overtop, and replaced it with an ordinary 15W fluorescent light strip. Over the past few months, besides being considerably darker than it was before, I’d noticed a huge change in the form of the Ranalisma rostrata in that tank.

Witness how the grassy plant looks in my 40G. Compact growth, overlapping each other, where each blade is thin and relatively uniform.

In my 20H, the growth is quite different (below), with blades more resembling a sword plant, than grass. The blades are longer and the growth is much slower. I suspect that the plant is sending out broader leaves to try and soak up more light since less is available. The color is also slightly different, with the broader leaves being a bit more pale, with a yellowish tint, where the regular form is a bright green.

I’m sure that this same phenomenon is present in a wide variety of plants, which is why it’s difficult to say exactly how a plant will grow in another person’s tank. I’m often asked at GWAPA meetings whether a plant is high light or not. In general, I can usually only respond that I’ve only ever grown it in high light, but that they should try it out, and see if it survives in their tank. Now, I can’t even guarantee that it’ll look the same!