rstampa

I've been fertilizing my recently purchased Vals with root tabs and liquid fertilizer. My light is set from low to high through out the day. All my plants are thriving and doing quite well. However the Vals are just doing nothing. Three months now and have some growth but on 2" tall. I just don't know how to get these guys to grow taller. I tried everything. They are planted in my 65 gal tank. Setup over 18 years. Any suggestion would be grateful.