When using sand I always just like to coat a gravel base. Gravel makes water movement easier through the base.
I also have a Penn plax canister cascade filter 1200 running in the same said tank as well would that work as replacement for a thirty gallon? If I take the undergravel filter out will that help?If you have an undergravel filter, the sand would work downwards under the gravel and clog the filter. If you want sand you'd have to remove the UG filter*
But removing the UG and gravel would remove the filter from the tank as well as removing the substrate so it's not as straight forward as just changing the substrate. Obviously you would need a new filter as well, so it would be advisable to get that first and run it for several weeks before removing the UG.
*I assume this is the type of UG comprising a plate with holes under the gravel and the water is sucked down through the gravel, under the plate then up an uplift tube?