> I have boesemani, dubs, threadfiins and praecox that are laying eggs
every
>day at pH 6.6. A friend has millenium and irian spawning at 6.8, another
>with splendida at about 6.8. All are heavily planted, CO2 injected tanks.
>Judging from the number of people frequenting the aquatic plant list who
>have rainbows in similar tanks I'd hazard a guess that pH is not the
>problem. I haven't had a sick or dead or sluggish rainbow since I increased
>the amount of surface agitation to increase the O2 levels in the tank --
>something that is a bit contrary to what most plant people recommend.
As to the plant people, the problem is just that you spend more time and
money refilling your CO2 tank if there's lots of gas exchange, no? (You'd be
amused or shocked if you knew how often I refill mine. No O2 problems ever,
though.)
A non-fish-breeder's testimonial: Most of the M. lacustris in my tank
(planted, CO2, pH 6.8-6.9) are the result of an accident involving a large
wad of Java moss left in there for a while so that the clown loaches would
clean out any snails, following which it went into a clean and unpopulated
tank, following which I noticed an odd shimmering at the surface, followed
by PANIC where do I find fry food NOW? followed by a couple of dozen very
nice little lacustris. A good thing: the parental generation(*) were starting
to get a bit old from some earlier periods of high temperature and poor tank
maintenance. But the point is that these lacustris, or lacustres, can breed
like bunny rabbits at this pH. Still, I've been thinking of cranking up the pH a
little, producing more lacustral conditions, though it will require adjusting
hardness to keep the plants happy.
(*) To reassure the breeders: no hybrids, certified good stock, bought at the
RSG convention in San Francisco several years ago, from two sources, one
being Julie Z.
-- Dan Drake dd at dandrake.com http://www.dandrake.com/ porlockjr.blogspot.com