Growing out fry in filterless tubs

[BenAquatics]

I've noticed that some breeders will grow out fry in small tubs or small containers that do not contain filters, but will do frequent water changes. Is this safe for the fish? Even if I do water changes 1-2x a day, won't ammonia build up in between water changes?

[JettsPapa]

I had tubs outside last year for the first time.  They were heavily planted with either guppy grass or hornwort, and stocked with guppies and shrimp.  I did occasional water changes of around 25%.  There was no filtration or artificial air movement.  It worked fine.

[gardenman]

Will ammonia build up between water changes? Yes. But small amounts of ammonia aren't necessarily bad depending on the pH and temperature of the water. A lower pH water can have a lot of ammonia in it. If you have higher pH water, you have to be more careful. The toxicity of ammonia increases dramatically as pH rises. Temperature also plays a role in ammonia toxicity. A cool water, low pH container can have an absurdly high level of ammonia and perfectly happy and healthy fish (assuming the fish like cool temps and a low pH.)

[JettsPapa]

On 1/11/2022 at 8:48 AM, gardenman said:

Will ammonia build up between water changes? Yes. But small amounts of ammonia aren't necessarily bad depending on the pH and temperature of the water. A lower pH water can have a lot of ammonia in it. If you have higher pH water, you have to be more careful. The toxicity of ammonia increases dramatically as pH rises. Temperature also plays a role in ammonia toxicity. A cool water, low pH container can have an absurdly high level of ammonia and perfectly happy and healthy fish (assuming the fish like cool temps and a low pH.)

Are you sure about that, in heavily planted tanks?

[gardenman]

On 1/11/2022 at 9:58 AM, JettsPapa said:

Are you sure about that, in heavily planted tanks?

There are quite a few articles on pH and temperature related to ammonia levels. If you Google/Bing/whatever "pH and ammonia toxicity" you'll find several articles about the relationship including one from the University of Kentucky that goes into detail about it in fish producing ponds. In a heavily planted tank, the plants may absorb much of the ammonia before it can harm the fish.

[GameCzar]

I use a nano sponge filter in my growout tub, but still lots of water changes. 

[BETTA999]

i breed fish fry and its not a very good idea to not have good filtration