Couple Questions
 

1. I'm using a giant rubbermaid tub that I found out back to hold some live rock from my tank for a little while. What can I use to properly clean the tub without contaminating the water?

2. Is there a special way to add snails to a tank or do you just dump them in?

3. What would you say is the best size pump to use for a Beckett 3 skimmer? Is a Mak 4 enough or would a larger pump do a better job?

Re: Couple Questions
 

I wouldn't use the old tub for fear of contaminating the LR, but that's just me. Maybe someone else will offer some suggestions.

2. Is there a special way to add snails to a tank or do you just dump them in?[/quote]

Acclimatize them as you would acclimatize fish.

3. What would you say is the best size pump to use for a Beckett 3 skimmer? Is a Mak 4 enough or would a larger pump do a better job?[/quote]

Haven't a clue. Someone else can answer this better than I.

If you're sure the tub never had anything bad in it, hot water and vinegar. Not sure, spend the $4.99 on anew tub.
Snails - I've drip acclimated and dumped them right in. No difference IME.
MAK 4 is easily strong enough for your skimmer. A MAG 18 would even be fine.

I just dump snails in, actually have better luck than when I try acclimatize them.

Steve