new tank questions: biofilter, sand cleaning, guppy control

NetMax wrote:
You would need to specify the system used or describe it better. The
higher your plant-fish ratio, the more you rely on organic filtration
instead of biological filtration.

Well, we went up there today and it was an error, the biofilter includes a
pump. Anyway, their homemade aquariums are only available in 2 colors
and my wife doesn't like them. She like the style of the Rena Aqualife
Classic so i might end up with the 150cm one which is approximately
500 liters.
http://www.rena.net/cgi-bin/trans.pl...yle_aqualife_c
lassic.shtml
It seems like a decent setup, with an external pump and 2 heaters.

You don't gravel vacuum sand in the conventional way, just skim the
top to suck up and detritus floating there. Also, as plants spread
out, you gravel vacuum less, so as to not damage the root network.

That makes sense.

There isn't much bacterial value in old tank water. Move your old
filters over (or the dirty filter media) for a few weeks and you will
cycle fine. Don't bother with fishless cycling. It's just not
applicable in your case, with old filters available and lots of
plants.

Woohoo no long cycle time. Yeha!
I'm planning to first put a lot of plants in, put the fish that i have
now in (very low fishload compared to the size of the new tank) and
move the old filters from the 2 aquariums in and leave them in there
like you suggested. Then leave it running like this for a couple
of weeks.

I'm not sure how good Dwarf gouramis are at pest control, but with
everything else, it should control the numbers somewhat, but it is a
139g tank and that's a lot of hiding spots.

That's what i'm afraid of, lot's of hiding places...
Hhhhmm. And if i get the big tank, the 2 smaller tanks need to
dissappear so my 40+ guppies would need to go to the big tank.
I'll ask the LFS if they want some.

So i hope that the other fish are going to be eating enough
fry to keep them from overrunning the tank.
Any other pest-control fish that would fit well with the current
batch?

Anything fast with a mouth which is big enough will do the trick. How
about 5 Giant danios?

Excellent, i'll have a look at those.

Thanks
Benedict