How can I get my Amazon swordplant to grow taller in my 29-gallon tank? It was almost a foot tall when I got it, and the first leaves it put out were almost as tall, although with shorter stems since it was now growing submerged. Later, the leaves kept getting shorter and thinner. Although the plant puts out a large number of leaves, it now is no taller than the anubias nana, hardly the eye-catching center piece I had hoped for.
I have a plain gravel substrate with a couple of spoonfulls of laterite near the swordplant. Lighting is 55w compact fluorescent, 10 hours a day. PH about 7.8, water moderately hard. I place Flourish tabs by the swordplant and add a little Kent micronutrient liquid supplement every few weeks.
Hornwort and anubias grow fine. Dwarf sag is pale but sending out new plants with runners. An ozelot swordplant that came in a tiny pot now is almost as tall as the underachieving Amazon sword. Algae is under control ever since I put in some vine-type ivy stems and let the leaves grow out of the tank. I think it sucks up the nutrients the algae need.
Tank is lightly stocked. I do partial water change and gravel vacuum about once a month, less often than before, but plants grow better now.
Is the problem a nutrient deficiency? Any suggestions to make the swordplant grow bigger?
Thanks for your help.