Originally Posted by David48atTD
Mate, we (the extended Thai Family) are Fish Farmers.
Without going into great details if you have a gentle ripple on the ponds surface there will be usually sufficient aeration of the pond.
O2 saturation levels depend, amongst other things on the ambient Water/Air temperature and the time of day.
The point of lowest O2 saturation is just before dawn ... so that's when you want your pump running.
If you want some fish for eating, monosex Tilapia or Catfish are the easiest and Catfish don't worry much about O2 levels.
Be carefull of the locals ... they'll nick the lot the night before you harvest them!
Many thanks for the info on O2 levels David, much appreciated. If I do come to installing a pump, it'll be on a timer and as you say, probably only needed in hot and dry season.
As for fish types, my friend's pond just up the road has Nile Tilapia (Pla Nin) in it that do very well, and are tasty (not at all muddy like carp can be), We can get these for a small outlay up at the reservoir (Huay lan) as the royal project there has a fish farm. I do like Snakehead fish (they also don't mind low oxygen levels), but I've heard they are voracious and eat everything else in the pond.
Anyhow, will do more research after house build is complete, the site for the house is very close to the pond and we'll be putting in a sala which sits half over the water, so I'll wait.
Fish for eating will be the last to go in after planting out.