We ordered some plants for a member, we were given this plant free because it was not doing well. We were told it was a Alternanthera Reineckii. According to what we have read it is suppose to grow 10 to 20 inches high. The attached picture started out as 1 stem and has bushed to what you see but will not grow up. What are we doing wrong.
Just for other info: 55g tank, 2x54w (was 4) t5 lights, EI dosing and pressurized CO2. Light on about 9hrs. All my other plants seem to be doing fine. All the other stem plants require weekly trimming. Maybe this one just forgot which way up is.
It is not Lobelia. Lobelia is bright green (that picture you linked is not a very accurate dipiction of lobelia). It is alternanthera for sure. The plant grows fast under the right conditions, but I have experienced some difficulties with it. Sometimes it gets distorted growth at the tips (new growth) and then it tends to stunt and put out side shoots. Other people have experienced the same problem, without a clear understanding of why this happens. it looks like some of yours are doing the same thing (curling). The likely culprit is low/inconsistent CO2 supply. Try to keep it stable and make sure you are supplying enough to balance with the lighting thrown at it.