It is a very good investment. I bought a 35 gal one three years ago when we were going on a one week trip. I never used it. Last year went camping with other family members with trailers and my brother had some newbies and filled up both gray tanks in one night. They didn't realize when doing dishes and taking showers without sewer hook up you can't let the water run. Well we had to dump 70 gallons of gray and it was the first time I used it and it was worth it's weight in gold when your in a situation like that. It is always in the bed of my truck when ever we hit the road. Just make sure they have a dump station within their camp grounds, you will never be able to lift it in your truck alone your looking at about 270 lbs. to lift if needed too.