Inspect your flasks regularly for contamination and growth progress. Some plants will grow slowly and others faster. Provided they are growing uniformly, growing leaves and most importantly roots, all is in order. Write in your notebook the date of replating, the number of flasks replated and other details such as additives used. In most cases the plants will have to remain in the flask for a period of not less than 8 - 10 months before they can be taken out.
Plants are ready for unflasking when they have several pairs of leaves and strong and healthy roots.
They will by then have reached a height of about 3 inches or more. The medium is by then practically exhausted. It is a good idea to move those flasks that are ready to be unflasked to the same situation in your greenhouse where you will want to grow the seedlings a couple of months earlier. While still sheltered from pests and diseases the plants can acclimatize the light and temperature conditions and thus 'hardened' before they are taken out of the flask. To unflask we prepare a dish with water and add a teaspoon of fungicide.