I had some questions on the sandbox, so I thought I would extend it a bit with some tips.
STAYING CLEAN
First of all, we all know how OCD clean I am. The sandbox can be quite annoyingly dirty--and sand gets everywhere!
For babies, put baby powder on baby's bottom before going out. The sand that gets in her diaper (and it will) will come off more easily. If you don't have/like baby powder, try cornstarch. I am not positive it will work, but they are similar so it is worth a shot.
After your kids are done playing in the sand, use baby powder to clean the sand off. When you apply baby powder to sand-covered skin and rub gently, the sand literally comes right off. This is great for the beach, too.
BUGS
Bugs are annoying. Don't they just bug you? HA! Okay, how do you keep bugs out, and once they are in, how to do you remove them?
To keep bugs out, it is going to depend on the type of bug. Ants seem to like sand a lot. Black pepper can deter ants. Try sprinkling a perimeter of black pepper around the sandbox. You can also try red pepper or dried mint.
Bugs tend to like moisture, so to keep bugs out, be sure to keep your sand dry. In our dry climate, this is not a problem. But if you live somewhere that is humid and/or moist, you will likely need to dig up and turn your sand regularly. If you have a small rototiller, you can use that. We use that every so often on our sand just to keep it workable.
If you have ants in your sandbox, try dumping three gallons of boiling water down the ant hill. I suggest you do this during nap time when the kids aren't around. If you pour this on plants, they will likely die. Do this when the ants are active and close to the surface.
Another way to kill bugs is to cover the sandbox in black plastic for a couple of days. The heat should kill the bugs.
For fleas, one idea is saturating the sand with salt water.
If this doesn't work, I would recommend you go in to a local garden store (one with employees who know what they are talking about...in other words, avoid the big box stores) and see what they recommend. Be sure they know this is for a children's sandbox. It needs to be safe for children.
SANDBOX CARE
Exactly how you care for your sandbox will depend on the type of sandbox you have. There are the purchased, pre-made sand boxes (like a turtle or crab) or homemade/constructed sandboxes.
A common tip is to keep it covered. The biggest problem with sandboxes is cats pooping in your sandbox. We don't have problems with this because we have two dogs who love to chase cats, but you definitely don't want pooping cats in the sandbox.
Covering the sandbox also keeps rain off the sand. This is good for preventing bug colonies and also for preventing rock hard sand. There are definitely better types of sand than others for sandboxes. I suggest you do your research and test the sand both wet and dry to see what you like. We buy our sand from the companies that use dump trucks to deliver such things (but you can use a truck or trailer to get it yourself). Stores like Home Depot and Lowe's also sell sandbox sand.
Turn the sand every so often. If it is small enough, you can use a shovel and a rake. If it is large, go for the small rototiller.
You don't want the sand to stay moist, so if it is moist, dry it out in the sun before covering again.
You can also strain sand with a colander or toy sand strainer. This is something your child will love to do.
If a premade sandbox gets wet, turn it and leave it in the sun. One built at your home will have natural drainage and the water should move down, but again, if you are in a humid climate, keep your eye on it to see if it needs to be dug up to help it dry out.
We make our sandboxes. We made one in our last house. We have a nice large one at our new house, but it is old. The sand is old, the box itself is old and is breaking down, so we will be building a new one this summer. It is our next major project. It is great fun because the box is large enough for all three children and several neighbor children at the same time.
MIX IT UP
While children love the sandbox, they are human and get bored looking at the same thing over and over. We dug a huge hole in ours and it was a whole new sand box. The kids loved playing it this new hole. Add some water and it will create a new experience. A new toy or toy will bring new fun. Try a hill. Change things up to bring variety and spark new fun in your child's imagination.
Hopefully this answered some sand questions. Let me know if you have more. Happy playing!