I am new to this LQ thing, got a really good deal on a 3 horse with an LQ with a few known problems....all were really simple fixes except one.  The grey water tank is broken and needs to be fixed, I am going to get it done but just haven't gotten it in yet.  We are going to couple of shows this weekend and I would like to have the toliet working.  If I fill the fresh water and no one uses the sink or the shower I think it should work fine....is that correct?

Should work. The toilet is usually the only source for the black water tank.

If the gray water tank is ABS, it might be able to be repaired. If it's polyethylene, it can't usually be fixed by a DIYer.

Thanks Gard.  I did try a fix but it's really broken and I got such a good deal on the trailer I think I will just replace it now rather than having someone fix it now and then again later.