Can I use clear plastic storage containers for egg hatchery’s?

[GaryE]

I use plastic containers for killifish eggs. I wouldn't use them for other fish.

Heaters can damage plastic. They slip, they disfigure. I never use heaters in plastic tubs.

I always leave cichlid eggs and fry with the parents. Broodcare is a Cichlid instinct, but it's an instinct that can be lost if it isn't modeled. It's a thing for commercial breeders who want huge numbers to 'steal' eggs and move them. Since I'm a hobbyist and want to see what my fish do, I never do that. The exception was always primitive mouthbrooders like mbuna, where a quick succession of spawnings can wear a female out, and there is no care for freeswimming young. Taking the eggs and letting the female recover can save her life. There though, you need an egg tumbler for the eggs and larvae.

There is zero evidence methelyne blue does any harm. None. I find its main function is that unfertilized eggs absorb it. This lets you remove unfertilized eggs (large eyedropper or turkey baster) if you have a pair that doesn't know how to do this task because they are inexperienced or the result of bad breeding practices. I don't think it protects eggs from bacteria or fungus, but it makes it easier for you to do so effectively.

BTW - many large plastic tubs (if you want more than 20L) will lose their shape with water in them. What they hold on paper and what you can pour into them can be very different.

 

[Lynnzer]

2ltr tubs seem a bit of an overkill. Surely the best thing is a number of small tubs of less than half a litre each, or even smaller initially, perhaps even as small as an old coffee jar. That way the addition of infusoria doesn't get too diluted and difficult for the fry to find.
I'd say the time to move them into bigger tubs/tanks is when they are eating regular albeit small flake or daphnia/brine shrimp.
Keeping several of the smaller tubs is easy enough if they are then left to stand in a larger tub or dish which can be filled with water and heated as a whole. Any potential fungal passage between eggs is also constrained doing this.

 

[felicebehaviour]

As was mentioned by itiwhetu, you just need to make sure that this plastic container is food friendly. Also, I suggest you try to use stand-up bags to store your food. Personally, I use various plastic packages for different types of food. Also, I love using thermal plastic bags when I'm going on trips with my family, and they keep food heated and fresh for a long period. If you are not sure if your plastic container is food-friendly, I can suggest you buy the various plastic bags from this site https://www.interplas.com/stand-up-bags. If you get any questions regarding plastic packages, you can always reach their customer support.