Don't know what they are thinking when they install the storage compartment as the fittings will NOT slide in. I found plans for storage tube that looks to be just ideal, made from 5" square vinyl fence post and gutter.
See at: http://rvbasics.com/techtips/RV-Sewer-Hose-Storage.html
Think I will install across front of trailer just behind batteries.
The indicator lites installed in tanks seem to work good until you use the tanks. Just before we left on vacation this summer I filled both my grey and black water tanks about 1/3 full and dumped in some Calgon. We left on vacation and when we stopped for the first night at the RV park with full services I hooked up and dumped the tanks as normal. You should have seen the black crap "pun intended" that came out of both tanks. Surprise, the lites started working again so the sensors were clear.
By the way, it is not the most pleasent sight of course, but I recommend that you use a clear plastic elbow, 90 or 45 degree, at sewer connection so you can monitor how things are going. It's very important that you don't use too much TP as it is the biggest cause of black tank problems.
I always tell users of my toilet "one or two sheets at a time, if you get some on your fingers that is why the sink is so close." Also is is very important that you use a TP that breaks down easy. We use Charmin Basic and it seems to work great but I think that any "septic safe" TP would work. If unsure put 1 sheet in glass jar, fill 1/2 way with water & put on lid. Give it a slight shake and let sit for a minute or so. If the TP has not disolved I would not recomend using it in RV. By the way, if you have the bucks, TP designed for RV's is good.