Many wild freshwater fish (trout being a good example)grow to a certain size depending on their diet, the conditions of the environment and their age.
You could, for example, stick a salmon in 60cm tank. It would eventually reach a point where it wouldn't physically be able to grow beyond the confines of the tank but it certainly wouldn't survive for very long at all.
I'm not sure whether what TetraLinz said (about organs continuing to grow) is correct. But this issue transcends animal welfare, it's cruel full stop.
Re: Do Cycle Products Actually Work... (you decide)
Although I don't speak from experience with aquariums, in most freshwater systems you can't just simply introduce micro-organisms that easily.
First of all, a whole myriad of factors will influence bacteria establishment and diversity from levels of dissolved organic carbon, particulate and dissolved organic matter (on which to colonize and metabolize), temperature, pH, light attenuation, turbulence and more.
Admittedly in an aquarium several of these factors will be non existent(i.e. unlike real water bodies, aquariums experience very little water turbulence). However as with in natural systems, bacterial communities will develop in relation to the conditions of a tank.
Now bacteria are quite hardy little chaps but not all of them can survive everywhere. For example if you were to go to lake and analyse the bacteria free-floating on the water surface with those attached to biofilms on the substrate, you would see massive differences in the species. The same applies for your aquarium - essentially the bacteria that are being sold in these products have been cultivated - you are taking a gamble that they will establish in your tank.
Even with products such as bactinettes, I'd imagine that once you add the bacteria, a large proportion will die off simply because conditions aren't right for them. If any do survive then great but I seriously doubt many tanks will be mimic the exact conditions required.
In my opinion (and remember a lot of this my opinion, I'm no microbial expert) these products only provide the detritus, DOC, POM and DOM that bacteria metabolize - essentially bacterial food. This will probably help establish bacterial communities more rapidly, but as for enough bacteria to mature a tank in 2 days? I'm doubtful.
Well I did tell him they would be my first fish in a newly cycled tank - I said I was looking for something hardy and I had narrowed it down to platys and zebra danios. I also have what I considered (until now) a decent fish book and it clearly says that you should have more males than females. Still, we learn from our mistakes.
While I have your attention, how long should I wait before stocking new fish? I bought the platys at the weekend and the water levels all seem fine. Just wondering because I'd quite like to get some danios soon!
I didn't put this in emergencies because I don't think it's that urgent (well not yet anyway). I'll post my test results though:
ph: 8 Ammonia: 0 Nitrite: 0 Nitrate: 5 Temp: 25
Tank is a 60l Tetra Art tank (57cm x 30cm x 35cm).
Anyway, I've had the tank since Christmas, I cycled it with fish food for over a month and did all the necessary water changes. I bought 4 platys this weekend, 3 male and 1 female. All are faring well, feeding readily, behaving well etc. I've been checking the water quality daily, just to make sure the tank has cycled properly.
But I've noticed my female platy is respiring pretty rapidly. All the males are fine, they aren't showing any strange behaviour. The female sometimes sits on the bottom but shows no signs of ill health apart from fast breathing - it almost looks as if she is panting.
I've also a bit worried about one of my males, who appears to be bullying the others a bit; any way I can discourage this?
Ok I haven't had time to take pics but I remembered that there was a thread on here about Tetra Art lighting. If you see here (scroll down a bit) and you can see a picture of the lighting system of a tank that is identical to mine.