Second what BDM says about checking the tap water. Never a bad idea to check it periodically, I've found that around here the parameters in my tap tend to shift seasonally. I've never had ammonia in my tap, but I do get nitrates in there in the spring, or after a lot of rain, especially - and I've read a lot of people on here who will also get ammonia readings in tap that can shift and change, depending on what's going on in the world.
Happy to hear those water sprites are doing so well for you! *dances* For the swords, I can only see the one in the front, but you might want to pull it up just a little bit. They don't like to have their crowns covered, so you want to be sure that the spot where all the stems come together, just above the roots, is above the substrate. I'd also consider separating them, and giving each their own root tab. Swords are heavy root feeders, especially when they're putting out a lot of new leaves. I've found that when I plant them very closely together, I'll have one or two 'hog' the nutrients from the others, and grow much faster. From the shapes of the leaves and stems, it looks to me that these sword plants were grown emersed (out of the water, on dry land). This is really commonly done with these plants, because they grow much more quickly dry. When they go under, it can take them a few months to slowly transition to their underwater leaves - so they'll really be needing the extra nutrients right now as they go through this process. Once they start thriving, you'll have to separate them, anyway - they're gonna get BIG (hopefully!)
Looks like things are going well for you!!! I hope you get your ammonia issue figured out. *worries* How high has it been, typically? It sounds like you're on top of it, with the water changes, but hopefully you'll get it under control soon! Keep up the good work!!!