So I am going to start AG brewing. Currently I have been doing extract and just did my first 10 gall extract batch and want to step up to AG. I am going to use a cooler for my MLT and have some questions. I was looking at some coolers today and the ones i was looking at 50 qt and 70 qt both have wheels on them. because of the wheels there is a step inside the cooler so its not completely flat. Should I definitely get a cooler with a flat bottom. Will the step cause and issues while mashing. At the moment I plan on using a copper or pvc manifold. Thanks in advance.