I am looking at the advantage aqua dog is that just for certain breeds ?

My dog has been on nexgard but i would now like to try advantage. Does it work for ticks too and how safe is it for a dog

How often should i use this on my dog? Mine is 14years old

We have a 22lb puppy and is 3 months old.... Is that medicine good to give him?

I have a 8 pound and a 9 pound dog, can I use the same dosage of Aqua Advantage for 8.8 pound dogs on both or do I have to buy 2 differeent dosages? or the weakest dosage.