I've had this prayer plant (four of them in the pot, I believe) for about two months and for the most part it's been doing great, but I have a few concerns now.

I moved about a month ago, and several leaves developed brown tips around this time, but otherwise still happy. The plant moved from a north-facing window to to the side of a west-facing window, and the additional light seemed to do well, and many new leaves sprouted up. More recently, the growth has comparatively slowed. I think that I may have underwatered the plant the last few weeks: the new place is a few degrees warmer, I run a ceiling fan most of the night which may dry the soil out more quickly, more energy may mean more water consumption; all in all, it seems I need to water more often to keep the soil evenly moist.

Over the past week, I had a leaf turn yellow over a few days, starting at the tip and spreading across the leaf, I cut it off a few days ago. Another has started doing that, just at the tip right now. Is this a result of underwatering? I've also read that individual leaves have a limited lifespan and will eventually die off. The two that have yellowed are smaller, lower, likely older leaves.

Since I'm uncertain what this guy needs, I checked out the roots, and I'm wondering if the plant needs to be repotted to allow further growth (although growing season is coming to an end as we get into September). I'm new to houseplants, so I can't really tell if the plant needs to be repotted. I've included an image with the area that has the most visible roots.

Thanks for any help.

DFish!
It might need a new pot, but more than that it loves a humid environment; I would spray the plant daily with water.

Also the ceiling fan will cause it to lose more water from its leaves by transpiration. It's not unusual for the oldest leaves on a plant to turn yellow and die, that would be normal ageing. Leaf tips turning brown often indicates a problem such as too dry (either soil and/or atmosphere) or too much fertilizer. From what I remember these are not among the easiest of plants to keep going.

Thanks for your replies. I do try to mist it at least once a day, since I live in a drier climate. I may also set up a humidity tray.

When plants are relocated, their environment is altered and so are their watering requirements. Increased light, temperature and air circulation will all contribute to a plant's needing more watering. It is also common for older leaves to die back some in response to a changing environment. You seem to be mindful of those changes and are making the appropriate adjustments.

Your plant most definitely does NOT need repotting. Plants do best when moderately potbound. That means when the outer rootball is almost entirely covered with a webbing of roots. As long as a plant has enough soil to go several day or more between thorough waterings, then it does not need a larger pot.

Misting does not improve humidity for more than about 15 minutes out of a 24 hour day. Marantas will do fine in low humidity as long as the soil is kept properly moist. If you want to raise humidity, use a pebble tray or a humidifier.