Water Chemistry For egg Scatterers

[Mr Gumby]

Hi folks,

I've had good success with egg scattering that are happy to breed in my very hard water, CPD's, Emerald dwarf Rasbora, most Corydoras etc.

However I watched the recent member talk with Randy Carey and he covered adjusting water for breeding of soft water spawners but he never followed on with the post spawn part.

My question is at what point do you start to bring the parameters back to your tap water? Can you start once you've collected the eggs - Once the fry have some size to them and are eating proper foods or at some point in between?

Anyone have experience good or bad?

[Fish Folk]

I think your goal is to avoid osmotic stress — cellular efflux or influx of water. Basically, fish balance their cellular integrity in particular concentrations of hardness or softness. What challenges them is the transfer from one set of parameters to another.

To your question, I think that fish fry are reasonably well developed by 1-month to begin a transition. I would go slowly, changing 15% water weekly over the course of a full month with clean water measuring at your target water parameters. After four weeks, theoretically 60% of the water has been converted. 

Other aquarists — out of necessity — just “drip acclimate” with an air-stone over the course of a day.

Much depends on the hardiness of your particular species and stock. I tend to think that large water volumes are preferable, along with large surface areas.

Slow, steady, deliberate. Make notes to learn from.

Edited March 30, 2023 by Fish Folk

[Mr Gumby]

Thanks @Fish Folk that makes sense. I'm currently slowly adding ro to my weekly water changes to reduce the hardness and pH. It was what I do after breeding that had me scratching my head