[Luca]

I don't think shipping water along with a mop is really what we are talking about here: trying to match the hatching water parameters with the spawning water parameters when receiving mops in the mail. Lets not complicate this for someone doing this for the first time. This is not critical unless the water at either end is at an extreme, it just may increase survival rates.

If one is spawning and hatching fish at one location, then this is not necessary as general water chemistry should be pretty much the same whether aged or new (dechoronated, reconstituted or fresh out of a well).

[Mark~N]

If your speaking of bow's personally I prefer vials over mops because I really don't like someone else's water in my tank anyway.plus I always know what I am getting by count.But if you have a mop tossing it in a well established fry tank regardless of water parameters makes no difference and if it is a species you got that requires some calcium so a handful of shell grit is fine later or before..As far as PH and GH that makes no difference either.Temp is the most important factor.they coming from an egg not a tank of water and don't know any better and you can easily meet there values by adjusting the water as you go along.I have hatched out plenty of different species eggs received in vials in containers with freshly declhored water and upon hatching dumped them into established fry tanks ranging from PH 7.0 - 8.0 and GH 4 - 18 and saw no fry loss because of it from any current fry going that were placed in any available tank.Only losses I can remember were in a new tank setup that wasn't cycled long enough or egg vials that were filled with tank water.

[Mark~N]

here's something I always wondered though.. In the case of my gertrudae.I know now that with a PH of 7.0 or lower and a variable GH I get more males than females.this being hatched out only in adjusted tap water that has been dechlorinated.So my question would be... at what point of this development stage does the sexing actually occur in the egg?.eg: minutes,hours days..
reason i ask is if someone sent these eggs and during the 3-5 day priority ship in alkaline water would me adjusting the water to neutral or below still have the ability to effect the sex outcome or would there be time still for manual adjustment of sex determination as it would in a nextday ship?.or even at all? been wondering about this for sometime...

[Luca]

Thanks for the clarificaitons Mark.

[AussiePeter]

Sex determination varies both in terms of when it happens (up until the fish are several weeks old) and what parameters (temp, pH, hardness, etc) change it too. Basically for rainbows we don't really know. Some folks suspect there is an effect, but no is sure what it is. There are other factors that play a role too such as you don't know the sex until they mature, but there might be differences in survival between the sexes (males tend to do better and grow faster) that has nothing to do with sex determination.

Cheers
Peter

[Mark~N]

Thanks Peter for the info.

[plaamoo]

How do you keep the temp up and steady in these small hatching containers??
I'm experimenting for the first time with some eggs from my (Mark's)kamaka. I made a mop yesterday and got 5 or six eggs the first day, 60+ today! I wasn't prepared for this. I have them in a tupperware on top of one of the tank lights but at night it cools down too much. Any tips??

P.S. Thanks for all the great info so far! Jim

[mikev]

My approach: 10g tank with a heater, filled only enough to cover the heater, place containers inside. If you do something like this, make sure to check for evaporation daily.

[plaamoo]

Thanks Mike. I think I can work that out.