sump question

[Mouse]

Hi,

I have been doing research on sumps and refugiums. All the setups I have seen, have a section for the skimmer and another one for the refugium and they flow to a central chamber where the water is then returned to the tank. Why doesn't the water first travel thought the refugium then go to the skimmer and then return to the tank?

Also I noticed that in all the tanks I have seen including sumps the water that is getting delivered to the tank is released at the top of the tank. Wouldn't be more efficient for water flow and nutrients for the entrance water to be released at the bottom of the tank, since the water is being returned at the top of the tank?

Thanks,

Aaron

[Zarathustra2]

Hi,

I have been doing research on sumps and refugiums. All the setups I have seen, have a section for the skimmer and another one for the refugium and they flow to a central chamber where the water is then returned to the tank. Why doesn't the water first travel thought the refugium then go to the skimmer and then return to the tank?

Also I noticed that in all the tanks I have seen including sumps the water that is getting delivered to the tank is released at the top of the tank. Wouldn't be more efficient for water flow and nutrients for the entrance water to be released at the bottom of the tank, since the water is being returned at the top of the tank?

Thanks,

Aaron

One of the best parts of a refugium is all the copepods and other planktonic animals it releases to your system. So, you don't want to skim after. You also are pulling a bunch of the dissolved organics the macroalgea uses if you skim before so a split setup is often used. Pre-skimming is better than post skimming however if the dual setup is not possible.

If your sump effluent is going to the bottom of your tank and your pump fails (or is just turned off) then your entire tank will drain into your sump. This is easily avoided by having your return at the top of your tank, usually with a siphon break. And before we get into one way check valves, they are considered very unreliable in a saltwater setup. Minerals, especially calcium, like to encrust on them. Also, the nutrient mix isn't that much of a concern with most systems having a minumum of 10x flow through powerheads ect.

[caferacermike]

On the other hand,

Maybe you haven's seen my system. First it is delivered into a filter sock prescreening area and then a pass over about 20lbs of live rock rubble densely packed, from there it flows through a bubble trap and into my skimmer area, next it makes a 180 degree turn and flows into the return chamber. On the way back to the tank I have a small line that runs back to a small refugium that flows back into the skimmer return. I've never looked at the overflow from the fuge and saw hundreds of little pods riding to freedom. The one here or there that makes it over is probably not going to be had by the skimmer as hundreds of gallons of water flow directly pass the skimmer and only a small portion is actually sucked up into the skimmer.

Basically your sump can be built just about any way that you can imagine.

Also the main point was not made as to why you remove water from the top of the tank in a reef tank. The dissolved organics and oils will float to the surface of salt water because the water is so dense. By removing water from the bottom of the tank you might get a lot of the heavy solids but you won't be removing the stuff that really counts, the already processed waste. It is these oils and such that are exactly what a protein skimmer removes.