chihi 寫:
I am sorry I don't know the name of the grass. But if I "連根拔起", do I need to cut the roots before I put in back.
yes, that is the normal practise, and will work for most aquarium plant.
Some plants allow us to just trim off the top part without taking it out, the plant will grow new branches from the cuting point, and gradually grow into a very densed area, with plants like this, my normal practise is to trim off the top 2-3 times, then pull the plant out and trim off the bottom and plant the top back to the aquarium again.
You should understand that there are hunderds or even thousands of plants in this hobby, so unless you can provide a photo or a name for your plants, otherwise we can only comment in general terms, which might not be very helpful to you.