Sump Question

A "sump", in and of itself, does nothing for #2.  Current/circulation can be accomplished using power heads and/or closed loop external pumps.  But you're getting the idea.  Just think of a sump as a place where you can put all your filters (algae/sand/skimmer/UV/ozone/reactors/bioballs), heaters, monitors, and anything else you might want in the water but not in the tank.  It's an added benefit that the tank water level stays constant while the sump level drops.

A sump can be as simple as a $5 rubbermade tub from walmart or more complex and expensive then your tank.  Decide what you want to do in your sump then work on finding a container that will fit it all.  Sumps are cool... but really they're almost the simplest thing in hobby.

I would recommend an auto top off for your sump. You do see the water drop in the sump and not the tank... I was adding 2 gallons of water a day.. The auto top off valve was on 21.00 at Mountain Shadow...

Check out my sump before you buy one. Look for the thread
ultimate sump. I built this really cool sump, and then a couple of
months later, Rob got a new tank and I got his old 50 gallon, which
is now my sump! You can have the "ultimate" sump if you have room
for it....for free!! (It's not really the "ultimate" sump, but the price is
ok,huh?)

Adam, you are doing the right thing by studying sumps.

Check out "RDP Refugia" by reading the Sea Star Online article concerning this type of sump. (Blue button to the left - Feb 2002 issue) Seeing them in action is the best way to plan one and the best investment you will ever make for your aquarium will be to become a member of the WMAS and, with a member directory in hand, call and go see some refugia, at your new friends homes.

For me, simplicity is bliss. I use an open container and large powerheads for my sumps.
Here is a pic. Call me anytime to come see it in Centerville, just 10 minutes from downtown SLC. My number is below.

Willi was wondering what my sump looked like.  I can't attach the picture of the refugium on the left, since the file is too big.  It's about 30g worth of fine sand, rubble, and 9 types of macroalgae. 

What you're looking at here is the right side.  You can see one T joint coming down from the downspouts in the main tank.  There is another T joint above the refugium.  The ball valve you see here used to have a floss bag on it.  We ended up having problems with that.  It got coated with algae, overflowed, causing bubbles & it was a whole mess.  You can see the skimmer.  You can't see the pump, which returns 1200gph back up to the main tank via a Y joint, which connects to two sea swirls. 

Hope all that makes sense!