Hi Dan, welcome to the Valley of the Sun. If you haven't been here during the summer, you'll soon learn why it's called that :)

I'd move that plant into a 1 gal container. Something like these (You can probably find them cheaper than that, I just linked the first one I found) I have some theories, but I'm not sure of why this helps so much. I find if you fit a plant into a container close to the size of it's roots, it does so much better. This means you have to re-pot most plants at least once a year, but it keeps them so much healthier. Once they are past the 7 gallon point, you can put them into whatever type of container and they do fine.

Then, I'd fill it with heavier soil, citrus love heavy soil (that means the soil has less air space like clay soil does, but I don't recommend using clay in a container). It's pretty much the opposite of what it looks like that plant is in now. Slightly sandy soil is best. I find it's best to make my own mix of soil rather than try to find the perfect soil from a store. I would add very little perlite to the mix (if any at all). Also, the soil needs to be compressed down and not full of air pockets, roots like oxygen but not air pockets.

I think this is the most important: get an automatic watering system if you really want to grow things through the summer in containers here. In the summer, they should be watered daily with just a little water (I use 1/2 gph emitters for 8-10 mins every morning for my 1 gal plants). If you miss a few days of watering (depending on the age/type of plant), the plants will most likely deteriorate to the point of no return.

Lastly, I'd make sure it gets around 6 hours of direct sunlight each day, but if you can, try get it some shade between 11AM and 2PM after April since it's young and in a small container. It'll be best if it gets this type of sun for it's first 2-3 years of life.

BTW, Everyone will tell you that you shouldn't waste your time growing a citrus from seed because it probably won't grow true to its parent, but I say meh to that. It's fun growing from seed and this is how all the varieties came to be. They were a seed once from either some genetic experiment or nature's crazy mutant child.

Thank you for the detailed reply!! I really appreciate the advice. I will go out and purchase a bigger pot this week. Also, I gave the little guy some water and a healthy dose of sunlight and it perked right back up this afternoon! I think it olé em sprouted another leaf! I will keep you posted on my progress! Thanks again!!!

- Dan