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Questions about Sumps [retitled]

Oct 9, 2006
Ok, the whole idea of a sump is something I understand. But what I need to know is what all do I need for a sump? Like, what parts are there to a sump, what makes the sump what it is and what do you need to make it effective and useful?
A sump is simply a smaller tank set below your main tank, with water flowing between the two. The sump is a place equipment that might be unsightly or dangerous to the inhabitants of the display tank.

Installing a sump requires three things:

1) The sump itself: Usually a smaller aquarium that sits in the stand.

2) A pump: sends water from the sump up to the main tank through a vinyl hose or PVC pipe.

3) An overflow: this is installed on the display tank and returns water to the sump via gravity. This typically includes a box inside the display tank who's top edge defines what the water level will be in the display tank. Water "overflows" that edge and is sent down to the sump via a hose or pipe. In this way the flow back down to the sump is always balanced with the flow through the pump.

There are two basic kinds of overflows. The first, and best, involves having holes in the glass of your aquarium and the box installed around them. The other way is a hang-on-back overflow that uses a siphon to transport the water in the box to a second, external box. From there it flows into the sump.

I know those things, but I need to know what you have to keep inside the sump to keep it running, like, what does the actual filtration. What I'm actually looking for is a list of parts like the protein skimmer and stuff.
I'm not sure what you're looking for here. Obviously you know about protein skimmers. Are you looking for information on biofilters? Most commercial wet/dry filters "replace" the sump in that the water drains directly into it and is pumped directly out of it back to the tank. I personally wanted the best of both worlds so I built a wet/dry inline before the sump.
To be specific, I know that there is the case made of acrylic or glass. But what I need to know is what goes into the plain old glass (or acrylic) box that makes it a filter. What does the filtration? I know that you don't just have a clear box with water running through it and back to the tank. So what makes a sump a sump?
You can use baffles to seperate the sump tank into sections. You could make one section into a wet/dry filter with bio-balls, another into a refugium with live sand, maybe some rock, and macroalgae. This is a great way to maintain a constant pod population in your tank and the macroalgae feeds off of the bad stuff in the water, helping filter the water and oxygenate it.

Check out this link: http://www.melevsreef.com/links.html There are some good examples.
superwaterguy52;82453 said:
I know that you don't just have a clear box with water running through it and back to the tank.

By definition, this is all a sump is. A sump doesn't need to do any filtration or anything to be a sump. Its just a box with water going through it.

Some things can be added to the sump for filtration. A skimmer and a refugium are the obvious choices, and a wet/dry filter is a good idea but makes it a bit more complex to design because the filter media need to be above the water line. That's why I put mine inline and not in the sump itself. If you do a Google image search for wet/dry filter you'll see most sumps designed for this have the water level low and the media raised up a bit. For this reason its difficult to design a sump that has both a wet/dry filter and a refugium or skimmer.

Well, I guess what I really need to know is what the stuff does. Here is what I'd actually like to know:

:confused: What is a refugium and what does it do?

:confused: What is a wet/dry filter and what does it do?

:confused: What are these 'bioballs' that I keep hearing about?

:confused: What is the sump actually? Is it the whole filter setup or just the little box?
The word sump has a broad definition. Any tank attached to your main tank can be called a sump. Technically "just the little box." Often the filter is in the sump, more often the refugium is; but neither has to be for it to be called a sump.

A refugium is usually inside a sump. Imagine the sump aquarium with one section partioned off (usually with baffles) with a sandy bottom and some macroalgae. This is a breeding ground for some of the influential little organisms in the tank like amphipods etc. Ideally the pump is in or near the refugium so some of these guys get 'exported' up into the main tank. The pH of your tank water drops a bit at night because photosynthetic bacteria aren't taking up CO2 when the lights are off. If you put a light on the refugium that only comes on at night it will keep the pH more even.

A bioball is part of a wet/dry filter, which I will explain below. It is a little tiny ball that is made up of a bunch of plastic folds or needles so that it has a lot of surface area to it.

A wet/dry filter (also known as a trickle filter) is the queen mother of biological filtration. The bacteria that turn fish pee into more benign substances like oxygen. If you want a whole lot of these bacteria you want to create a lot of surface area for them to grow and make it exposed to air. The best home for them is to have a box full of bioballs and have your tank water trickle through them.

Power filters and canister filters are much less effective because the beneficial bacteria are always underwater and don't get as much oxygen. Some power filters have a "bio-wheel" that gets wet and spins to get some wet/dry action. The downsides of a wet/dry are they take up space and you have to make sure the water that goes into them has a good prefilter because there's a lot of space for particulates to get caught and decompose.

This is what a bioball looks like. If you can imagine a box full of these things, you can see all the area there is for bacteria to grow.


Here are two pictures of commercially available sump with an integrated trickle filter. These are the same piece, but one picture shows the bioballs in it and the other doesn't.



The water flows from the aquarium onto the drip plate with all the holes in it. From here the water trickles through all the bioballs, which rest on the black grid (which is called eggcrate). The middle compartment holds a sponge filter, and then the pump sits on the right.

This is a decent design. The water level is around the top of the sponge, which means only the bottom layers of bioballs are underwater (remember they work better when they're not submerged). Its generally difficult to integrate a wet/dry filter into a sump because you need to have a low water level. Its hard to run a skimmer or do anything else (like a refugium) with a really low water level.

The other alternative for a wet/dry is to put it before the sump, as I have done.

Here are two very good threads (Of course they're good, I started them :lol:). The first is my education in filtration as I was asking questions as I planned my tank:

Tank renovation - Filtration

The next thread is photos of my finished setup.

Tank photos - Finally!

You'll learn a lot from these threads. They should be required reading for ceph-keeping; if I do say so myself :smile:

Having read all the linked material, I can honestly say "my head hurts!".

Some incredible info there!

The book I bought relegates the use of a sump to "more advanced" aquarists, so I've been searching for this info.

Michael Blue;92679 said:
The book I bought relegates the use of a sump to "more advanced" aquarists, so I've been searching for this info.

That's fair. Especially given that we relegate the keeping of cephalopods to more advanced aquarists :smile:

I hope my threads are valuable to newbies. The level of experience I have--paltry by comparison to a storied reefkeeper like Thales--was earned slowly through multiple iterations of equipment and costly mistakes. And hundreds of hours pouring through old threads on sites like Reef Central. Many people come to this site looking for a how-to on setting up a complex system and to some degree I see the lack of discipline or interest in finding the details on their own as a proxy for a lack of the requisite attention to keep these animals properly.

Above all, I think the threads linked above provide a logical narrative of sumps and filtration that are more conducive to learning than any syllabus or article I could ever write.


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