rubbermaid add-ons

I was thinking about moding my rubbermaid before i get started like a drain system for when i need to flush and a way to get fresh water and nutes to the system with out opening the top of the rubbermaid.

Any ideas?

It's easy to add a plastic drain valve made for a hot water tank. I don't have one on my new tote, I now use a wet vac. On top I have a rectangular access hole. When not in use it is covered with a piece of blackout fabric with velcro all around. Another thing is paint. Paint it all black, then all white over that. I also cut a well-planned hole for the 4 airlines to the 4 airstones.

thanks illegal smile. so with the wet vac u made a hole at the top and just stick the hose in it to suck all the water out?And when u say paint do u mean paint the outside of the rubbermaid?