how big of a tank is needed for convicts to breed like SOB's ? would a 30gallon (30lx12wx18h) be large enough to house a far load of em ? I would like em to grow to about 1-2" before they get used as food....and can I just use a sponger filter in the tank ? or do I need a HOB ... do convicts eat there babies or would they eat the smaller ones once they see them when there growing or ?