If you are finding that the bottles are leaking around the screw ring, this normally indicates that the round silicone valve at the base of the straw has become damaged, torn or that the water added to the bottle has been a little too hot. You should notice, on the domed valve, a small split running across it. This allows the air to flow up the straw and out of a small air hole. If the water has been a little too hot, or the valves are torn, this can cause liquid to enter the straw and travel up to the air hole on the screw ring.
If you find that the valves are damaged or torn; please contact our after sales immediately 043232500 or email us at firstname.lastname@example.org