Thanks to TYNK 7, Vicki S and Sean!

I've read up on Bio-Spira, and the critiques of Cycle. Unfortunately, I
haven't found any Australian sites that mention Bio-Spira, so I'm guessing
that it's not available here. Damn. And unfortunately I don't know anyone
with a mature tank to beg some gravel or filter media from. So, I'll stick
with your advice, and let the cycle complete naturally before adding any
more fish.

I'm testing every second day, and everything looks okay so far. Will do 20%
water changes at least weekly, more often if the ammonia and nitrate get
much higher. My 3 little platys are still doing fine, healthy and active
and eating.

I am not familiar with the product you asked about..Geoliquid. What is
this?

I haven't tried it yet: thought I'd ask if anyone here was familiar with it.
It's actually a range of similar products formulated for different
environments, but basically it's a Japanese mineral extract known as
"Bakuhanseki liquid". I understand it supposedly works by colloidal bonding
with minerals, chemical contaminants and bacteria, to clear the water and
help establish the bacterial filter. It's marketed in Australia by Avico
International as Flex Geo Liquid Mineral Magic.

Regarding my "wish list", I'm now trying to decide whether to set up the
tank for brackish water species only. Most of the fish on my list that are
common locally have been bred in freshwater conditions and should be
acclimated, although I understand that most are supposed to benefit from
added salt. So I might be better off opting for all brackish species. I'm
thinking now about:

Brackish tank:
- a couple of dwarf corys (c. rabauti) or bumblebee gobies
- 5 platys
- a molly or female betta
- 3 celebes rainbows or Pacific blue-eyes

Freshwater:
- 2 bronze, albino or peppered corys
- platys (as above)
- molly, swordtail or betta
- a dwarf coral/neon blue gourami and a couple of pearl danios OR 3 dwarf
neon rainbows.

(I'd still like a peacock gudgeon, though!)

Thanks again for your help. I'll let you know how I'm getting on.

Vicki PS