So, after talking to several people who have seahorses, it seems the preferred method is to hand feed them one shrimp at a time with some tweezers until they are full. That way you don't overfeed and you can keep a close eye on the seahorses' appetites and notice immediately if anything is wrong. I feed them as much as they want, which seems to be around 5-6 shrimp for these guys. The recommended amount from all the breeders is 2-7 shrimp twice per day. My two have already figured out that the tweezers mean food and they'll eat shrimp right out of the tweezers. Luckily they've gotten super easy to feed now that they have their appetites back after shipping