John, I'll accept that for the most part lower pH values aid in the success of breeding apistos. It probably has as much to due with lowering the bacterial count as stimulating the spawning partners. In the wild sudden lowering of the pH is probably caused by waters invading the forests during the rainy season and leaching out tannins from fallen leaves. Whether it is the increased rainfall, increased breeding habitat, or lowering the pH that stimulates them to breed isn't really known for sure - maybe a little of each. Your highly skewed sex ratios may actually be the result of there being a lot of subdominant "sneaker" males. Try separating the males from the group and see if more of them pop up. If it is truly skewed toward females to this extent, then it has more to do with the temperature in the rearing tank than the pH in the spawning tank. Cool tanks (72-75ºF/23-24ºC) tend to produce considerably more females. pH has some, but not significant, effects on aggies. Mike Wise John Wubbolt wrote: > Hello All > > Ok I've got a question for you all. Does pH really hinder some species > from spawning or does it trigger them to spawn all the time? > > Here's my dilemma. A friend ( Joe Hildreth) came over lately and > wanted to test my water in some of my aggie tanks, as he was having a > problem getting his to spawn where as mine spawn like convicts. When > we did a pH test of a couple of my tanks, we found pH range of 4.5 to > 5.0. I hadn't realized my water pH was that low in some of my tanks, > so we tested my tap water pH and found it to be a pH of 6.0 and <1 > degree carbonate hardness and <1 degree general hardness. My question > is, Is this too soft? And would the low pH hurt my fish. So far from > general observations, the pH doesnt seem to affect my fish, some really > seem to love it. > > I guess i just was curious if anyone out there has similar experiences > with water conditions. I think i need to some crushed coral to one of > my next Cacatuoides grow out tanks, as i have one tank that looks to > appear like im gonna have over 70 females and not too many males.. > > John > > ------------------------------------------------------------------------- > This is the apistogramma mailing list, apisto@listbox.com. > For instructions on how to subscribe or unsubscribe or get help, > email apisto-request@listbox.com. > Search http://altavista.digital.com for "Apistogramma Mailing List Archives"! ------------------------------------------------------------------------- This is the apistogramma mailing list, apisto@listbox.com. For instructions on how to subscribe or unsubscribe or get help, email apisto-request@listbox.com. Search http://altavista.digital.com for "Apistogramma Mailing List Archives"!