Planting a potato in a pot is one of the only instances I know for planting a newbie plant in a big pot. You need a larger pot, 3 minimum and 5 gallon maximum. What size of pot are you using? I am amazed with twice a day watering it is still fine. You could dig down and take a peek to see if your potato start has become slimy or mushy. I'd get your potato, soil and all plunked into a 5 gallon pot...USE POTTING SOIL. Do not use garden soil. Most potting soils are fairly acidic, which potatoes need. Don't get me going on garden soil being used in pots. Lots of other answers on this site you should read about that subject.
I love the transparent pot thing. Is there a drainage hole? Easy to transplant. Just keep your hand over the top of the soil and turn upside down. Wack it on the sides or bottom smartly and it should just fall out. Put it in its new pot that you've put POTTING SOIL on the sides and bottom (and firmed that soil)to allow your rootball easily placed. You HAVE to have at least 1=2" below the rim for watering. Do not water unless that soil is dry at least an inch below the surface. The soil should be moist, never wet all the way to the bottom of the pot. Then allow to dry before watering again. Throw out any schedule you might have.
If there is a mass of roots go ahead and 'fruff' them up, loosening them from the 'mass'. Make sure the soil (moisten first) in the new pot is firmly compacted (not concrete firmly) beneath and on the sides of your pot. Add soil and gently but firmly press to get (large)air pockets out of the soil and tuck your potato in its new bed.
This is a perfect situation to try growing potatoes vertically. A 5 gallon pot will allow quite a few potatoes but growing vertically you'll get bigger ones. All you need to blow your office mates away is a couple hand sized potatoes.
To grow vertically, get a wire cage, even a tomato cage will work fine. When you finally get 8" of green top growth, start piling in straw around the green plant so that only 4" of leaves are exposed. When the plant gets 4" higher, add more straw. Keep going. The potatoes will grow in the soil and the straw. Get some burlap to line the inside of your cage as you add straw. Don't do the entire cage all at first. Lift the pot off the floor with tiles so that the drainage hole has lots of air below. NO gravel or rocks beneath the soil above the drain hole just potting soil. That soil HAS to be sterilized, purchased potting soil.
Use a tray beneath to collect drainage and bits of soil. Soil coming out of the bottom will stop by the second watering. Water the straw lightly, and focus on watering the soil. Do not water until straw and soil are dryish.
Potatoes need light. The photosynthetic leaves FEED the roots and their other storage units (potatoes). Luckily they don't need as much light as do tomatoes or other vegetables. Use a 'balanced' fertilizer such as Osmocote 14-14-14. Keep that first number equal or less than the second two numbers and DO NOT over fertilize. Osmocote you can get by with 2 applications during the entire growth season.
When your plant flowers, shortly afterwards the tops will die. This is normal for potatoes. Go ahead and poke around in the straw and soil for new potatoes. Eat whatever you can find EXCEPT...Do not eat any GREENED potatoes. This means a potato has seen the 'light', the skin starts to photosynthesize and is quite toxic. It is after all in the same family with Nightshade (Solanaceae), tomatoes, peppers...if you see a potato peeking out cover it with more straw. Turn your pot every day. Hope your seed potato doesn't rot. They do so don't stress. Try again...?
