Help me figure out this JBJ nonsense filter please

[McCarthy]

So I bought this JBJ Desktop tank with build-in backwall filter / heater / pump canister. Looks great doesn't it?

Then I found some time and had a closer look at the filter combo, and came to the conclusion that this can't work properly for 3 reasons:

1.) The column for the heater to the right is completely closed off to the filter media column in the middle. If I'm not mistaken, the incoming water just flows right over into the middle section and can't circulate the heater element at all.

2.) The 3 filter media cartridges are also being mainly bypassed, and that little water that will go through the filter media will mainly go through only one media, the one with the least amount of flow restriction, which will render the other 2 very ineffective.

The entire filter section doesn't make sense if you ask me, because they are in parallel and not in series.

3.) There is no intake at the bottom, only the one at the top. How is this going to filter anything that closer to the ground? Why are the cutouts at the bottom only fake and not open?


Am I missing something or is this indeed a complete design failure?

This is the main water flow in my opinion. Basically bypassing both the heater and the 3 filter media cartridges:

Should I mod this filter? What needs to be done?

 

[KipperSarnie]

Here are my thoughts on this:

Heater:
The heater will heat the surrounding water which will in turn heat the tank but I suspect there is a certain amount of movement in this section as it acts as a heat pump. Hot water rises thus creating movement in this section.
If the bottom slots were open there would be a better flow but also you would require to clean your filter more often of debris. I assume JBL assume the filter is purely biological & not mechanical thinking that the owner would siphon debris at water changes.

Water Flow in the Filter:
Biological filtration does not need a high water flow, so by allowing some water to pass straight through you are reducing the water flow through the media.
What your diagram does not show is the filter boxes are fitted to a weir so that some of the water has to pass through the media.

Take a look here: