What kind of caulk to use?

[waste]

Joyce, nice pics! I would use either baking soda paste on a green scrubbie or Mr Clean magic eraser to clean up the area in question, let dry and apply white 'kitchen/ bath' silicone caulk. You could also use white grout to fill the areas, but it looks like the caulk was used before.

[JJParrish]

Thanks! I just sent you a PM to ask you to look at my post! We also have some line cracks in our concrete wall around the pool deck. Our pool is at least 14 years old (we think - we've only had it 16 months). I need more pics and will try to get some this weekend if my son comes over w/his camera. Thanks again & happy swimming!