With a busy schedule forecast for next year, I'm on the lookout for "low-maintenance" plant options to fill out a few non-planted spots in my tanks. Fore/mid/background suggestions are all welcome. I'm not looking for floating plants though.

My tanks are 20G and 30G, both with about 2.6 W/g of T5HO lighting in the plant-friendly spectrum. No CO2. I dose with Seachem Flourish and Potassium weekly, and occasionally Trace. I'm not using Excel currently.

What I mean by low-maintenance: plants that generally stay put, don't get too big, and don't require frequent trimmings. For example, stem plants that need to be trimmed/replanted frequently, or plants that produce runners, are disqualified. Obviously, some maintenance from time to time is necessary, but ideally this would be just a quick trim (without having to replant) or cutting off a few old leaves. Some good examples are sword plants and crypts, of which I have several and they are great, but I'd like to have more diversity. Also, I'm not looking for java fern or Anubias species.

Any recommendations would be much appreciated.