¿mis hojas no mejoran?Actualizado a month ago

As a rule, old leaves do not rejuvenate, as plants channel their energy towards producing new growth to replace old growth.

This means that a yellowing leaf, or one already damaged with algae, will not become green again, no matter what you provide. 

Look out instead for how the plant produces new leaves: with good nutrition, they should be richer in colour, be in better form and remain algae-free. For stem plants, you must replant the healthy new portions grown under APT, and discard the old stem and roots after the new portion has grown tall.

To read about how plants adapt to an improving environment, head here.

In this picture we transferred a Variegated Rotala macrandra from the shop's tank to ours. In the shop, under lower light and inadequate fertilization, the leaves are greener and the internodes are longer. After being planted into our farm tank, the new leaves produced are fully red, reflecting the higher light and fertilization levels. Notice however, that the old leaves that were grown in the shop did not produce this adaptation. They are programmed to best utilize what was available in the previous environment, and even an improvement in their new environment cannot change that fully. Individual old plant leaves have limited plasticity to optimize to new environments - the plant's strategy for adaptation is by growing new leaves that are optimized.

After the plant from the picture has grown in our tank for some time, we cut off the top portion that has been grown adapted to the tank and replant it, discarding the bottom portion (that was grown in the shop). The fully adapted plant preserves its older leaves longer, and even the old growth is more algae resistant as well. Notice that even the older leaves further down the stem are well colored and in good form as they are adapted to this tank.