Building sump

[Tseering23]

I'm ready to build my 125g sump, how big should my intake chamber be? Bean animal so two 1 1/2" pvc pipes for drain(no filter socks).
I had 12"-14", but now I'm thinking just 6"-8" should be better.

 

[Oughtsix]

It really depends on the design of your sump and how you want it to function. My sump intake chamber is half of my 55g sump. The other half is the return pump chamber. This works well for me and how I want my sump to work.

 

[duanes]

I agree about "design", and what your concept of a sump intends to be.
There are no hard and fast rules as to how any sump is to be built, as many people use their own specifications for what they want a sump to accomplish. Possible flow rate, submerged or wet dry media, refugium etc etc.
I use a 125 as sump, I put the pump and media in an area that in about 10" of one entire end of the tank, all media is submerged.
It is separated by a Porret Foam wall the height and width of the 125 (no walled off chambers), which is my only mechanical media.
The other 5 ft (or so) of the sump (tank) is heavily planted and used as a refugium for animals like shrimp that help process waste, detritus and algae .



I have used many other sump versions in the past, wet dry, fluidized bed, with differing media, like filter socks, bio balls, etc, etc and have tested parameters to see if one seems better than the other.
In most cases they have worked the same, and equally well.
What I like about the most recent experiment, the one above, is along with the bio filtration for using up ammonia and nitrite, in this version, is that nitrate is also reduced by the aquatic, semi aquatic, and terrestrial plants

 

[duanes]

Since each tank is different, we all stock differently, etc etc, this is why sumps are tailored to each aquarists own needs.
You may be amazed that the sump you set up today, may evolve into something totally different next month, once expectation meets need.
If you have reophillic fish (like most Geophagines, or Tomocichla) , that need lots of current, a wet dry with a low water level in the outflow chamber, may be too wimpy for a sump, the chamber may not be able to keep up with pumpage.
If a tank is overstocked, using lots of biomedia may be required, and half a 125 loosely packed with it may be needed.
If (as in my case), my tanks are outside, they get tons of leaf litter, debris, and falling flowers that can clog mechanical media.
I also use plenty of flow (at least 1500GPH) (I tried wet dry when the tank was first set up, and the two normal sumps, could not keep up).

The planted end is also always shedding leaves, so the Porret media could get easily clogged.

This is why the sump (refugium) is stocked with shrimp, to help break large chunks, into smaller particles the bio media can then process.