I haven't used any fertilization on my plants yet, so I think it is most likely an imbalance as you said. If I do a 50% water change, clean as much algae as I can from the glass and cut algae covered leaves... will this help keep the algae at bay?
There really isn't much info on the Aqueon LED lighting other than what the retailers say. The lamp comes with one tube which says it is fairly low light, but with three tubes I don't know what the wattage is. I'm not savy with lighting terms so "wattage" is probably not the right word so sorry about that. I will try to attach something.
http://www.aqueonproducts.com/products/modular-led-aquarium-fixture.htm
You're right, there is no data on the light. Perhaps other members are familiar with it and can offer advice. I see it can be expanded, if others suggest this.
Roy is correct on the two "non-aquatic" plants. But I would leave them for the present. The tall one is often called Fountain Plant, and is a variety (there are a few) of the species
Ophiopogon japonicus and many have this plant last for over a year submersed, even though it is strictly speaking terrestrial. The fern I know nothing of, though I have seen something very similar in the Vancouver Aquarium, perhaps the species Roy mentioned. I would suggest keeping an eye on them, and if either starts to rot, take it out.
I can't see algae issues on the plants in the photo. Algae on the glass is easily removed during the weekly water change; I clean the inside of the front glass and sometimes the side panels with one of those aquarium sponge-type scrapers every water change even if I don't see anything. A sticky biofilm naturally forms on all surfaces in the tank, and this attracts algae along with various bacteria and infusoria, so keeping the glass clean will prevent algae from taking hold.
Be careful removing leaves, as aquatic plants can move certain nutrients from older leaves to new growth. If new leaves are appearing, you can prune old leaves with algae over time.
As for nutrients, a comprehensive lioquid supplement is probably a good idea. Plant nutrients occur in fish foods (via fish waste that enters the substrate and is broken down by snails if any and then bacteria) but these alone may not be sufficient. I use Seac hem's
Flourish Comprehensive Supplement, and another similar is Brightwell Aquatics'
FlorinMulti. Both contain everything in proportion, and it takes very little. In your 29g, 1/2 a teaspoon added following the water change is all you will likely need. The light green plant in the foreground of the photo is a sword,
Echinodorus sp, and these are heavy feeders. Substrate root tabs like Seachem's
Flourish Tabs will help this plant; one tab placed within 2 inches of the crown of the plant, every three months.
Byron.