How much experience with salt water animals have you had?
They will not eat frozen at birth, only live food.
They usually eat mysids and then will eat small shrimp after they get a little larger, they can be successfully weaned to frozen food, although most people have found that their animals are healthier on a live food diet.
A 20 gallon is on the small side, but might be ok if you have a larger tank to transfer them into when they get bigger. Some people float them in a breeder tank inside a larger tank so that they can make sure the hatchlings are actually eating.
@cuttlegirl , look under the post and to the left side. You should see your name and the post date followed by a string of words, Edit Delete ... Report. They are bold but not displayed as a button (I see a few more words where you see the ellipse and am not sure what non-staff see) . If you click the word Edit, it will bring up an editing window for simple edits. In this window you can click the "more options" button for a full edit screen. If you don't see this, let me know what browser and device you are using to be sure we don't have a technical issue.
I posted a couple of hints for the new forum in a post called 2013-2014 Forum Tips and Tricks that I hope is helpful for some of the new navigation. Let me know where I could make some of the content more useful if I missed mentioning/describing something confusing.
Live mysis only way to go, I breed amphipods just for my baby cuttles and found they fill better with mysids.also they ate through my tank raised amphipods, they just don't breed fast enough to supply my cuttles.
So far, I am about a week and a half in to feeding 4 baby dwarf cuttles. I keep them in a breeder net in a 40 gallon. They do eat amphipods, but prefer mysis. I don't think there are any retailers selling mysid shrimp, you pretty much just have to either catch them yourself or if you're inland like me, order them off the internet. I knew this going in, though. The amphipods and (I have some form of shrimp population in my main tank) keep them fed between mysis orders, but as everyone else said, this is what they eat. Also, they hate being observed when they eat and only do it in total darkness.
Extremely sorry, being a newby, (upsetting some people), but PLEASE don't rush into Cuttles, they are not easy to care for when young. Reading all the posts on cuttlefish care will give you a good idea.