Tilapa grow slow

[peterk]

Had fish about 4 mo, water clean, well aerated, temp, pH ok, feed duckweed, water hyacinth, commercial feed, got reds from farm, 1" to 3", plus caught "natives" from local streams and put in, not overcrowded, now largest is about 6", haven't had any die in a couple mo, I understand you can't grow these in Aus.

[qwarla]

It's not legal in most parts, but I know of at least 2 seperate places within 10 -15 minutes drive from my home where they can be found in the wild.

People do fish there and I am sure they do catch them as well. You can see the little ones all around the edge of the water.

[Murray]

It is common knowledge that Tilapa are well established in and around Wivenhoe Dam, in the adjacent creeks and Brisbane River. Also North Pine Dam has a large population.

Evidently they are good eating, so, one would think people should be encouraged to catch and eat to help control their numbers.

[DaveOponic]

Had fish about 4 mo, water clean, well aerated, temp, pH ok, feed duckweed, water hyacinth, commercial feed, got reds from farm, 1" to 3", plus caught "natives" from local streams and put in, not overcrowded, now largest is about 6", haven't had any die in a couple mo, I understand you can't grow these in Aus.

That's very slow growth for Tilapia. Do you have cold water/climate?
My most recent batch of Tilapia fry have grown from microscopic to about 4 inches in about 6 weeks. Tropical water temps here. ( 28 - 32 C constant)

I think water temp. and good aeration/feed are the main growth factors with Tilapia.

[peterk]

Thanks Dave, water temp here, Belize, about same as you, will increase aeration, feed now as much as they will eat, several times a day

[DaveOponic]

I haven't grown red Tilapia. Mine are silver grey hybrids. I have just bought a new batch of pellets. My supplier has changed his source, the fish don't seem to devour the new pellets with as much enthusiasm. I got fantastic growth rates out of the Barra last year with the old pellets. They were high growth formula made in Taiwan - god knows what is in them....I would prefer to have more control over their feed but haven't had any luck with alternative feeds. They will eat the occasional worm and BSF larvae and hyacinth but so far the best feed seems to be pellets........ I even give them cat food biscuits on occasions if the pellets run out .... they like these but not economical.

[peterk]

Mine eat duckweed, hyacinth, commercial fish food, chickens corn, I'll try cat-food. They don't gulp at surface, but how do u know if aeration is adequate?

[DaveOponic]

Tilapia are a hardy fish. It takes a lot to kill them. Because I have grown Tilapia with Barramundi, I noticed a few things.... one is that the Tilapia copied the Barra behaviour of breaking the water surface to eat pellets. (Competition??) In a tank with their own species they rarely/reluctantly seem to eat at the surface.
The other thing is that Barra need lots of aeration and clean water.

The Tilapia that swam with the Barra ate more readily, grew faster and were more active than the same sized/aged fish in two other tanks.

I have a pond pump with 12 airstone outlets. I used about 8 stones in a 1000 litre tank. As far as I am concerned, you probably can't have too much air bubbling through the water. Not sure how you measure/ calculate the DO but I guess there are instruments or chemicals for that. I find the whole idea of regular testing tedious and don't have the time for it. After a few years with AP systems i think it becomes easier to test less and go by experience.