This is for people who have a shower and toilet in their popup. I need to get a bigger Gray/Black holding tank for the popup and wondering what size to get. It came with an 11 gallon but with 2 daughters and myself it filled up quickly just from washing dishes and using the toilet. No showers. I was thinking of getting an LX35 Thetford which is 35 gallons but when it is full it says it will be over 250 lbs. It does come with wheels but worried that dragging it through the grass to hook it to the ball on the truck will be difficult. So just wondering what other people do. Thanks!