Originally Posted by Tigerfish
Okay 28 gal tank has substrate: gravel and lighting: 17W bulb (tank is close to a glass door) hope that helps...
If the gravel is fairly small grained that is excellent for plants; it anchors the roots and they will grow well in the normal aquarium gravel, and it is easy to maintain. I'll assume the light is fluorescent, one tube. The wattage is odd, maybe it is one of the new compact types? Having the added natural light from a window/door is good, and it can always be shaded if necessary. I have a west-facing window in the room where I have my two aquaria. Make sure the tube is full spectrum, with a rating of around 6500K. The light should be on for a minimum 8 hours, and I would suggest 10-12 hours in your case as the wattage is low enough there should not be a problem with algae. Use a timer so it is consistent every day, and obviously make sure the light will be on during the time of day/evening when you would normally be viewing the tank.
I think the setup will work fine for rooted plants like those in my aquaria; if you haven't already, have a look at the photos under my "Aquariums" to see what we're talking about. Try some of the rooted plants like Amazon swords (Echinodorus species). E. bleheri (this is a very commonly-available species) will do well in moderate light, as will E. amazonicus which is usually a bit smaller, but neither will be too large for your 28g tank. E. bleheri particularly makes a nice "centrepiece" plant, set off to one side next to a piece of wood is a very pleasing and natural look. The pygmy chain sword E. tenellus and E. quadricostatus, another dwarf sword, should work; both these will send out runners from which daughter plants will grow and carpet the substrate. Anubia nana tolerates low light very well and grows very slowly; although usually sold as a "rooted" plant it actually grows from a rhizome that sits on the substrate or a piece of wood or rock and attaches itself by roots, similar to the Java Fern which is another low light plant. Crypts are good low-level plants, but many have trouble growing crypts--they are fussy about consistent water parameters and will melt into a blob if the temp or pH or light alters. But once a tank is established and water conditions are consistent, they are good low-light plants for the foreground. Sagitaria with its long slender leaves is a nice contrast plant, similar to Vallisneria; in my experience Vallisneria does better is slightly alkaline water (pH 7 or higher) with some hardness--in soft acidic water I cannot grow it. All of the afore-mentioned will do OK in "normal" water and will grow slowly, so there is little if any maintenance in the way of pruning, and the way to arrange the aquascape generally remains as you set it up.
Stem or bunch plants will probably not do very well as they are high light plants. I do have good success with Brazilian Pennywort in my 90g, but it requires weekly pruning as it grows very fast and would blanket the surface blocking out all light if I didn't keep it cut back. If you want floating plants (some fish spawn in their roots) the floating fern (Ceratopteris) is easy to grow; it produces numerous daughter plants from the leaves, and it is fairly easy to keep it in check as you can just remove the larger plants and let the smaller grow. I bought one of these in the mid 1990's and today I am still cultivating the successive plants in my 70g, and I throw out 3 or 4 every week. It is a fast grower, and a good natural filter because of that.
While tap water in some areas might contain some minerals, it is probably not enough for plants so liquid fertilizer will be mandatory. I use Seachem's Flourish Comprehensive, but have in the past had equal success with Kent Freshwater Plant Supplement. Start out once a week following the partial water change, using the dose recommended on the bottle, and keep an eye on the plants. If the leaves start to get a bit yellowish, do a second weekly dose. Swords in particular are heavy feeders and require iron to maintain green leaves and good growth (slow but steady). Not wanting to over-fertilize for fear of algae, I have twice in the past 5 months reduced my fertilization to once a week, but both times the plants started weakening within a few days (yellow leaves, some turning transparent like cellophane) but this clears up with twice weekly dosage. Things seem to be in that balance i mentioned previously.