Your 10 gallon is fine for a pair of convicts, get your female really fat and u will be fine. In my 20 plus years i have never had a problem breeding convicts in a 10 gallon, also never needed a dither or any special tricks to breed convicts. Keep you fish fish fat especialy your female and you will be fine. I have a pair in a 10 now i use the babys to feed my small gobys.