can high alkaline water cause fish not to breed?

[fishfishiam]

can high alkaline water cause fish not to breed?

[nabokovfan87]

Without much context, it's a yes. 

Some fish need certain PH water to breed or trigger breeding.  It's just one of the things that does that.  Some fish need high PH, some need low.  Just really depends what you're talking here in terms of specific species.

In the wild, some fish go through "flash flood" habitats after a storm.  The PH of the water shifts and then you have a swing in water parameters.  Some breeders replicate this.  Some species of corydoras need the KH/GH to be high and then have a certain type of water change to trigger spawning.  It's due to evaporation increasing hardness, PH, KH, GH, and then the rain comes and triggers those behaviors.

[T. Payne]

Some fish will breed and lay eggs but hard water will not allow the eggs to hatch. What species are you concerned about?

[fishfishiam]

Black mollys, White cloud minnows, and guppys

[JettsPapa]

On 1/16/2023 at 5:37 PM, fishfishiam said:

Black mollys, White cloud minnows, and guppys

I can't speak to the others, but guppies breed well in my 8.2 pH hard water.

[T. Payne]

On 1/16/2023 at 6:37 PM, fishfishiam said:

Black mollys, White cloud minnows, and guppys

All of the fish you are asking about, I have bred in high ph and alkaline water.