My growth is slow week 5 flowering auto

I was just reading about watering with cold water slows the grow I’m gonna be pissed if this is why my buds are still small and the grow is slow... I read that cold water induces lockouts etc so this whole time I’ve been using water from the tub faucet and it’s always cold when you turn it on... is this the case if so what’s a good temp for water

I grow is soil btw Thursday will make it 5weeks flower and I’m pretty sad cuz my buds look so tiny but I’ve read it takes 4-6 weeks flower to fatten up