My YWG (Cuthbert) and his pistol (Roland) are a very private couple. Cuthbert only comes out when he's hungry and I rarely see Roland; occasionally his claws peeping out of the burrow if I use a flashlight at night. Cuthbert will swim out onto their "balcony" and stare at me when he's hungry but won't swim into the water column at feeding time. I drop pellets near the burrow but it's hit or miss on whether Cuthbert collects them.
To make sure they're fed, I deliver food to them (they don't even have to call or tip!) via the Foodevator(TM). It's just a rigid piece of airline tubing I stick into the hole that leads to the balcony and drop pellets down it directly into their burrow. Takes the pellets a minute to get down the tube but it ensures the Odd Couple is getting fed and protects the food from Gertrude, the pig disguised as a Starry Blenny (she'll try to attack the pellets on the way down)
Unfortunately as said before your Frank is really skinny.
Since you've had him 2 years I don't know about parasites, but you should try to get some more food to him ASAP. Good luck!
You can use any food that won't get stuck on the way down and is heavy enough to sink.
