Two chamber vs three chamber AIO filter

[pauly2191]

Hi everyone,

Hopefully a freshwater question won't upset anyone. This forum seems to have lots more DIY stuff. I've recently got a Fluval Spec V going and really like the AIO filter (only 2 compartments). With the corona virus I've now got plenty of time on my hands and would like to DIY an AIO filtration system into a 20L I have. I've learned a ton from the numerous threads on here but one question I can't seem to find the answer to is why not just two chambers?

Its seems that the second chamber is used for a refugium, skimmer, cheato, etc and with a smaller freshwater planted tank I don't think I'll really need any of that. Thus would a two chamber system similar to the Fluval Spec V be fine or am I missing a benefit of the third chamber?

 

[Copingwithpods]

Although my freshwater knowledge is very limited I would assume (when comparing it to saltwater benifits) that a 3 chamber would be beneficial. Usually with AIO tanks the 1st chamber is usually at display level so no cascade effect is achieved from display to chamber 1.the real magic and adjustability comes from chamber 1 onward. After chamber one the media's and water levels can be infinitly adjusted via top offs. A center chamber has the benifits of cascading water while leaving the return chamber free for return pump, uv, heater and anything else. The center chamber can house bio media where 100%flowthrough can be achieved. With only 2 chambers the first chamber will have little to no flow near the bottom.

 

[Ratherbeflyen]

My question is what do you want to achieve with the filter? What are you trying to incorporate?

 

[pauly2191]

My question is what do you want to achieve with the filter? What are you trying to incorporate?

The aesthetics of the AIO are a big draw. I like that its contained within the tank compared to a canister (although really not any experience with them). Filtration wise it would be your basic filter floss, sponge, Purigen, and biological filtration. Nothing a HOB couldn't accomplish but the AIO looks better to me. In my limited experience I think the AIO is also much quieter.

 

[Ratherbeflyen]

Like Copingwithpods said, If you have a 3 chamber filter, all the water moves through the entire filter system.

If you have a 2 chamber filter, the water will take the path of least resistance and you'll have a dead spot. You'll also have problems with the surface collecting slime and floating particles in the second chamber, as there will be nothing moving to get it to a filter.

If you invert the first baffle, then you'll have a detritus trap for anything that doesn't float.

That's why you'll see most filters with 2 baffle and 3 chambers.

If you don't want to, or have the space, for 3 chambers, I would just go with one chamber and a removeable media basket.

(This a hang on back, but it only has one baffle to separate the sand from the pump inlet/return.)

Here is an walk through of an all I one tank I made 5 years ago and ran for 2 years. It actually has 4 chambers, the first chamber was to hold the heaters. The second chamber is what I mean by removable media basket. The 3rd chamber is very small and really only there to prevent the aforementioned dead spot and control the water height.

 

[pauly2191]

Thanks for the great post @Ratherbeflyen and the nice diagrams. Quite helpful. I should have room for two baffles and three chambers so I'll likely go that route. Won't necessarily need the extra chamber but much easier to leave empty now (or really fill it up with media/filtration) then add it later.