Not to be a smarta##, but why do you want to raise convict fry? They are so common pet stores won't even give store credit for them, and supply is almost always greater than demand. Granted, it's always great to raise a batch of fish from tiny fry, but you have to consider what to do with them when they outgrow the tank. Then there's the consideration of the next spawns. Most cichlids will spawn at least several times once they start, though they usually take a break after producing 4-5 broods (several hundred more fry from each).
I would suggest a predatory fish for population control, a raphael catfish would be a good choice for a 10 gallon tank soon to be overloaded with excessive numbers of fry.