Aptasia

[Delphinus]

They can easily get to 1" or more.

When you're using Joe's Juice, be sure to inject them. Use a needle instead of the syringe pokey thing they give you, that's just going to squirt the stuff on them. They'll come back.

Alternatively you can try kalk paste. Get a good thick sludge of kalk and inject the sludge at the bottom. Not the kalk water itself, that's just spicy water as far as they're concerned. Again, a needle works best but you'll need a thick one otherwise it will gum up. Try UFA, they have honking big needles there.

Shut the pumps off so the water is calm, and be quick. Also if they retract into the rock too quick for you, try feeding them beforehand. If they're engorged they can't squeeze into a hole as easily.