Well some can get infected and after a while you should be able to start seeing a black dot in them and this means that they are good. I haven't really looked into bubble walls but i do know that keeping them with plenty of oxygen can help them grow. If they stay white, then that means that they aren't going to hatch but just give it some time, i'll be looking into the bubble wall thing for now this is what i can offer but will get back to you on the bubble wall