I think there would be a lot of flexability with the adult and juvi tanks. They can be kept pretty packed and they may be less territorial this way. As for the breeding. One breeding adult pair will produce at least 100 fry each time, and as soon as the previous fry are gone they will breed again, producing fry at the rate of once every 2-4 weeks I believe. That means that I wouldn't put too much of the operation into multiple pairs. One will probably be enough, and to keep genetic diversity, I'd select a new pair each time.

I have a 55 gallon tank with, I just counted, about 25 juvuniles. I'll keep them for a while and let you know if I run into any problems with overcrowding. I have another tank with about 60 1.5 inch fry and maybe I'll wait till they're bigger and separate the sexes and let you know how that goes. It's just a hobby for me so it's no bother.

thanks man

they make sand bed filters for aquriums...

http://www.tmc-ltd.co.uk/commercial/fluidised-sand.asp

check this DIY filter...
http://pets.webshots.com/photo/11362991 ... 7345eYaUza

this one looks pretty cool...

Wouldn't a pool or spa filter be like a big version of one of those?

Hmmmm. OK. I thought the bigger the better. You do have ponds so you should know.