Re:Dwarf Seahorses for a beginner

Hello,
I was curious about this part of one of the articles that I have read:

I start the babies off in a one gallon gold fish bowl
with an under gravel filter and a plastic plant, you can buy a setup like this for
around $10.00. The reason for the smaller tank is two fold. First, you are able to
concentrate the food better, these little guys can eat a lot. Second, the adult
females will sometimes kill the newborns by snapping the back of their necks with
their heads.

I was thinking about raising the fry separately for the parents for food density and other factors such safety etc., but I am a little curious on what type of tank I should use for the dwarfs. I have seen the $10 tank in the above quote at Petco but keeping the water parameters in such a small tank would be a chore. I have found a 5g tank but it includes a power filter and even with a sponge attachment I think that will be too strong of a flow. I have found a 4g with an undergravel filter that seems pretty nice. Which one do you think would be best because I could modify the 5g but that would defeat the purpose of buying the aquarium.

Or do you think it is better the raise the dwarfs with the parents.

Thanks.