Compartment filters?

[Charney]

I am working on the design of my next fish room. My current room utilizes sumps and I overall hate them. They take up a lot of space and even with a backup generator, the thirty second delay can drain enough water through drip drain to potentially not have enough water in the sump once the generator kicks in. I am playing with alternative ideas. I will have a few 300 to 400 gallon tanks. A friend recommended looking into compartment filters to put in the tanks. Anyone have experience with these? Where to buy or how to make them? Best way to size them? I am also looking for suggestions for 700 to 1k plus pond filters. Though I imagine these will be sumps or Ultimas
I do love above tank sumps but the room is only 7 ft tall and some of the tanks will be stacked so doesn't leave much room

 

[Ansorgii]

I built my own compartmentfilters. I prefer them over sumps due to their heatloss and the limited space I have.

When it comes to designing them it really depends on what you want it to do, your waste philosphy, your focus (high flowrate, low flowrate, biological or mechanical), what kind of fish, cost, how often you want to clean it, etc.

Do you want to built them into the tank or removeable ? Both have pros and cons.

 

[jjohnwm]

I've never even heard the term "compartment filter" before; my google-fu is weak and I can't find it on there either. What does it mean?

I get that sumps take up a bunch of space, but they also add a significant amount of additional water volume to a system. If compartment filters go inside the tanks, you will lose this additional volume and the overall space available to the fish will be reduced by the volume occupied by the filter.

 

[Ansorgii]

jjohnwm

I understand this as an compartment filter:

Pretty bad design, but you can see what I mean.

Yes, you lose volume in your tanks, but they are incredibly efficient if designed well. And you can just make your tank bigger to compensate.

 

[Ansorgii]

As to why it is an awful design, the pump is a bad choice since it creates pressure when none is needed, a stream pump will be way more efficient and can easily overcome the 2-5cm height difference you need. That will save you 50-90% power for the same flowrate.

And just look at how much space is wasted, thats like 40% of the filters volume empty.

 

[jjohnwm]

Ah! So it is essentially just an internal box filter, scaled up a bit. By building it in like that, you are creating a much-larger version of the "all-in-one" tanks that are sold in pet stores.

In that pic, the water overflows from the main tank through the weir at the upper right and into the filter. That relatively tiny compartment containing the pump and biomedia is the one location where the water level with rise and fall due to evaporation, or due to removing or adding decor, gravel, etc. You'd need to be careful; simply taking out one good-sized rock or piece of driftwood, or perhaps a bucket of water when transfering fish out of the tank, could starve the pump almost immediately.

I think that a much better idea, especially when the OP is already planning on stacking tanks, is to make this filter much bigger and locate it in the bottom tank, and then extend the return line from the pump up to the top tank. Equip the top tank with an overflow that drains into the bottom tank. One big system, filtered by the "compartment". I'd replace the weir with a much larger intake, stretching down even to the bottom, and with a sheet of Poret foam as a prefilter. This way, the entire bottom tank becomes a sump, water level changes will be almost unnoticeable and very easily observed, and the pump will never be in danger of running dry.

 

[Ansorgii]

A further point as to why this design is awful. If the water level falls below the height of the whool the filter can no longer run and the heater is isolated.

Yes, thats essentially that. In my experience a thickness of 15cm is enough for a tank around 800l, you can really get a lot of filtervolume in without loosing to much of the tanks volume.

But you can always go bigger till you essentially have a parallel sump.

If you want I can give you a sketch of what I would consider to be the best unspecialized design.

 

[Krismo962]

Something similar i run,took up about 6" of tank space so I got a 3.5' tank made instead of a 3' to account for the space taken up by filter.

 

[duanes]

I use a similar "compartment concept" to separate the planted majority of my sump, from the small

1/6th side where the pump and bio media do its job.
It is separated from the planted side by a Porrett wall, that acts as mechanical media.

The shots above were taken years ago when it was first being built.
Today, it looks like this.

And I don't want my sumps stuck under a tank, I want room to comfortably do maintenance, and for the terrestrial plants that eat nitrate, to grow, far above the water line.

 

[dogofwar]

The simplest internal filter is a side wall of Poret. I use jet lifters and also place a box filter or two behind the Poret wall to keep things clean.

Also a big fan of overhead filters. If you use under-the-bed rubbermaid bins, you can have as little as 7" or so. I try to place the pump for the overhead filters behind the Poret wall as well.