Undergravel filter

[western44]

Hi all, i was in a lfs not my usual lfs and i noticed they had undergravel filters for sale, something that i have'nt seen for many years.
It got me wondering as i have a spare tank, would it be possible to run an undergravel filter with a small external filter, if so how would
you do it. Thanks in advance.

 

[_Maq_]

Tried in early 2000s with a powerhead on the uplift tube, but plants didn't like it. And I got used to the silent running so ditched the UG filter. If only there was a truly silent air pump !

What you say suggests that UG filter worked well only when the water flow was very modest. Is that so?

 

[_Maq_]

I am very distrustful of stagnant substrates, they may be natural but when wading through them the pong that comes up is very indicative of low oxygen.

Bad smell is not an indication of low oxygen. Of course, bad smell (hydrogen sulfide) develops only in anoxic conditions, but it does not mean that whenever conditions are anoxic, hydrogen sulfide develops (in noticeable amount).
As I understand it (and I've read quite a lot of literature about it) the substrate is always suboxic/anoxic, yet only if there's abundant organic matter present processes resulting in foul smell occur. In other words, if you keep organics low in the water column and the uppermost layer of the substrate (=keeping organic pollution low and oxygen high), then lower layers remain oxygen-free but bad smell hardly occurs.
This is the reason for which I'm wary of active/nutrient-rich substrates.