Adding plants after cycle

Skip the tabs. Since you've got a normal gravel substrate, choose plants that aren't big root feeders. This really doesn't limit you terribly, although it means no vals, crypts or Echinodorus. Anubias, java fern/moss, stem plants, floating plants will offer much in the way of variety. Check out the second picture in my sig. The 18 gallon is a new setup, really my first try at a 'low tech' setup. I'm using Hydrocotyle leucocephala as a carpet plant and so far it's working fantastically. Just bury the stem in the gravel and very gently pull it up to re-expose most of the stem.

All these plants will draw the majority of their nutrients from the water column.

Once the tank has been set up for a while, you should have enough mulm in your gravel to accomodate some root feeders, but until then, there's plenty of variety among the column feeders.
 
Also, when the plants grow how do you cut them? Just cut them with scissors. Won't that bother the plants tissue? If the plant grows up to far do I just cut it from the top? I heard that you pull the plant out and cut the bottom. What would you do with the roots? Sorry I am a newb at the plant thing. I have been keeping fish for 8 years and just decided never to use live plants.

Thanks
 
Never apologize for asking questions! :)

For stem plants, pull them up and cut just below the node (where the leaves/roots grow). I just use scissors and haven't had any problems.

While you're filling out you're filling out your tank, i.e. propagating, don't even bother pulling them up, just cut above where you see the plant branching, cut off the internode (the part of the stem between the leaves) and replant. The bottom will look ugly for a while, but after the branches grow out long enough you can plant the branches and toss the bottoms. Different plants will behave differently too, so that'll be something to learn too. For example, sunset hygro will branch from every node, Anacharis (Egeria densa) will only branch at certain points, you can tell where because two nodes will grow really close together, other points won't branch.

But yeah, once you've got your tank filled nicely, pull up, cut the tops so that they're between 1/2 and 1/3 the height of your tank and replant the tops. Toss the bottom or give them to a friend.
 
AquariaCentral.com