The reason for low TDS/PH for eggs?

[Berdel]

Hi

I have a few questions that i hope you can help me with regarding water chemistry and breeding. I don't think i fully understand the reason why we need to lower the TDS/MS for eggs to hatch and which effect the PH has when breeding.

To my knowlage, we lower to MS or TDS to match or get lower than the osmosis pressure inside the egg so that it will not implode and make hatching possible. Lowering the PH helps the parents to develop slime but does this also have impact on the eggs?

I am under the impression that if you harden the water too fast and change the PH while there are eggs on the cone, the eggs would get destroyed or it would result in a low hatch rate. I was told that water stability during hatching is very important.

I would really like to understand this right because i think ive got something wrong here...

[White Worm]

The pH...more specifically...gH (hardness) is important for egg membrane penetration during fertilization. Otherwise, harder water is preferred during hatching and raising stages by most. Hard water equals little fertilization due to hard egg membrane. Everyones water is different so it just takes practice to get yours where you need it. I keep the water soft with 2/3 RO and 1/3 TAP water (gH 3-6) until I see the eggs have been fertilized. I then start doing regular water changes with tap water. Just moved so I dont know exactly what my tap reads now. The discus seem to like it so thats good.

[LizStreithorst]

I have found that hard water hardens the eggs making it difficult for the eggs to hatch out. I don't start doing WC with tap untill the fry are attached to the parents.