In general (very general) UGF
/RUGF promotes very healthy roots. That is, the plants will have an awsome root system at the expense of good leaf growth. Roots will quickly clog the UGF
/RUGF. Also, UGF
/RUGF makes replanting a chore/mess for rooted plants due to the roots growing through the filter plates.
One will typically go RUGF in an attempt to hold off the time when a UGF
(might theoretically) go toxic due to excess waste buildup. With a planted tank, the plants consume the waste/nutrients that get trapped in the UGF
and make the tank more viable in the long term.
So, a RUGF is good (maybe/arguably) in a non-planted environment to keep the tank running longer. A normal UGF
will pull nutrients into the substrate which plants then use in a planted tank. Your plants will have healthy roots, and average to lackluster leaves (relative to the massive roots). These techniques are not very popular anymore, that does not mean they do not work. A lot depends on the tanks goal. I use UGF
's nowadays on some of my fry tanks. Combined with plants, the tank water stays very clean and I have less maintenace going on, so as to not disturbe the fry. Outside of a fry tank, if the goal is a nice planted tank, a good powerfilter is the more modern choice.
is a question relative to lighting for the most part. Filtration type does not factor in any major way for this decision.