Over time we expect the plastic to warp a little. Firstly, the growbed is not a perfect rectangle to begin with. But more importantly, the plastics used in the Water Garden are a bit more flexible because they lack some chemical hardeners like Bisphenol A. We wanted to make sure that none of these compounds would leak into the water and eventually into the food being grown.
The new growbed and grow lid, however, fit together in the current version; so when assembled, your Water Garden should not look warped. If yours is severely warped or you are experiencing functionality issues (like the feedcap not working) please let us know and email any photos so we can share with the team and get you a replacement.