If I purchase a food or potable water grade resin can I place it into the column and use immediately?

No, the resin may not be supplied in the required ionic form and requires regeneration to put it into the correct ionic form. Even if the resin is purchased in the correct ionic form, it is often still good practice to regenerate the resin if practical, if it is part of the plant's normal operation. This regeneration is important, particularly if the product has been in storage, to ensure the product is placed in service in optimum condition. Each manufacturer has their own recommendations for each resin in each particular application. Where the resin is used in a non-regenerable application, the resin manufacturer will still have a recommended procedure to condition the bed before use.