Alessa is right, you need to condition the pair before you spawn. Breeding is really hard on them, and if you just got them yesterday they've been through a fair bit of stress lately! The male normally won't eat at all while tending eggs and fry, the female expends a lot of energy making eggs (if a female doesn't spawn she either reabsorbs them or drops and eats them so regains the protein, etc), and both parents are going to be very active, and most of the time will have minor injuries they'll need to recover from, so have to be in tip top shape both to produce strong healthy fry, and to stay healthy themselves. Usually I condition for at least 2 weeks, feeding a mix of frozen foods and pellets. If you can get any live cultures even better!
The live plants will nourish
infusoria which will help get the fry through the first day or 2, you're right. After that the baby
brine shrimp are a good food. Make sure you have 2 hatchers so you can feed the fry twice a day (the brine shrimp are most nutritious immediately after hatching so it's good to have 2 separate batches daily for the twice a day feeding). It doesn't have to be anything complicated... I just have
airline tubing shoved into glass jars and it works well enough!
a 20 is a bit large for a breeding tank. It may work just fine for you, but if they're not spawning after being conditioned, you may want to divide it. For some reason they tend to spawn better when forced to be in fairly close company. Otherwise the female will often just disappear and hide and not come out! Most breeders use a 5-10 gal, and some even smaller containers (though that's not for the faint of heart or first timers... I've never worked up the courage to try myself lol)
It sounds like you're pretty prepared, have done your research, and have most of what you need on hand for at least the first month, so off to a good start. Depending how many fry you end up with, the 20 might not be big enough for all of them as they grow. Be prepared to do a LOT of
water changes either way (at least every other day, daily is better), they need clean, fresh water to grow well otherwise they'll end up stunted. You'll need jars, but you have a 2-3 month time frame to accumulate them, and that way you'll know the size of the spawn and how many you'll need.
That's about all I can think of for now, if you have any more questions ask away and good luck!
