Grow Out Tank Size: Go Small?

[WhyteMonkee]

I was reading this article as to what would be an appropriate tank size for growing out Discus fry. The person who posted this Steve MacDonald, suggests growing fry out in a smaller tanks.
http://www.macsdiscus.com/blog/discus-fish-grow-faster-in-a-smaller-aquarium/

I am sure that this is dependent on the number of fry you actually have, and the success is dependent on how well you keep up with your water changes. I am concerned with the health of the fish with this method. I would like to think that the more a fish can move around the healthier it would be. I do see how a confined space might make it easier for all of the fish to feed equally and grow at the similar rate. But, a hierarchy in the tank might be necessary to weed out fish with inferior genetics.

Some questions I have:
Would the high dependence on water change frequency make essential to have a multiple tank system to ensure stability in water quality?

Would you be consistently getting the same quality of fish form this method, or is this just a way to pump out fish that at a fast rate so they can be sold?

Does increased heat really speed up their metabolism?

I know I asked a lot of questions but feel free to respond to anything I addressed in this thread.

[Phillydubs]

I am thinking this suggestion is because you want to do big water changes - easier to change say 55 gallons once or twice a day then 125, you know?

People always say heat will increase metabolisim.

I suggest growing out in the biggest tank you can with the most amount of water changes... So if you can do daily 100% on a 75 but only say every other day or 50% on a 125 I say go with the 75.

[WhyteMonkee]

I am thinking this suggestion is because you want to do big water changes - easier to change say 55 gallons once or twice a day then 125, you know?

People always say heat will increase metabolisim.

I suggest growing out in the biggest tank you can with the most amount of water changes... So if you can do daily 100% on a 75 but only say every other day or 50% on a 125 I say go with the 75.

Sweet, thanks. I will keep that in mind. My home has particularly hard well water so I am dependent on an RO water mixture. I am investing in an AquaFX Barracuda 200GPD, and some barrels to age water with it.

Does the metabolism thing reign true or is it just a myth?