Pondage experiment over

[Ducksta]

A few people asked me to report how this finished up so here it is. ( I tried to take some pictures but none worked right )

Well I grew a few dozen fry (yellows and hongi) in a outdoor 200L fibreglass pond over the bulk of summer.

Results early on were some incredible looking yellow fry, but this was in the first couple of weeks while I was still supplementing diet with OSI cichlid flakes and a bit of frozen food occasionally (prior to the little ecosystem being self sufficient)

Once the water darkened, and the walls of the pond were a thick green matt of algae I stopped feeding extra bits.

Today I pulled down the pond.

What I found were some really dark looking yellows. Some of them were almost a green colour. I guess colour is influenced by the environment a bit more than I anticipated. The fish are really healthy, fat, and have grown very quickly.

The colour on the hongi was incredible!! I have similar sized fry growing out in tanks inside, and they are fairly light colour. The fry from outside (as small as 18mm) are an incredibly deep dark purpley colour, with orange finnage. I find this to be incredible!! They are so small, but they look like miniture versions of breeding coloured adults. I guess in the darker enviroment, it was better for them to take on the darker colour for protection. The growth rate for the hongi was also better than in tanks (even in tanks with better water quality, and higher volume)

The only downside was a slightly higher than I anticipated mortality rate. I doubt very much it was aggression as the fry are only just hitting 3cm (the biggest ones) and there are fry at around 18mm the smallest. (I started with a large variance in fish sizes) There is the possibility some of the fish were hunted by water beetles, or birds or cats though I guess. (Though I can't imagine a cat getting wet for a couple of grams of fish)

Conclusion: I am setting up a bank of tanks outdoors for raising fry over summer in future