How long to give fry growout tank?

[jameson_uk]

I have just filled a small 18"x10"x10" ClearSeal tank I purchased a number of years ago, mainly to save my wife from killing me due to the noise of the little hang on tank I am currently using (see here).

I have bought a Hamburg Matten Filter (ie. a little bit of pipe and a really big sponge) and have added a couple of cm of really find sand I had lying around. I have placed the sponge from the old filter in my Betta tank behind the matten sponge and I have also squeezed out the two sponges from the sponge filter that has been running in the main tank. Only plants are some frogbit

Question is, how long should I give it before moving the tiny fry / eggs to this tank? (literally just notice another 30 odd eggs too)

 

[castle]

Empty the water in the fry tank, refill with water from the main tank when you move in the eggs. Temperature should be the same, or 0.5 degrees more

10-20% water changes in fry tank every day with water from main tank