Re: Calcium requirements in water

> From: spush at saudan_HAC.COM
> Date: Fri, 07 Feb 1997 19:19:19 PST
> I suppose that about half of the alkalinity should be Mg.

The only reference I've seen regarding proportions are some charts in
The Optimum Aquarium.  They indicate roughly 75% Ca and 25% Mg. 

> > 40 mg/l might be fine for plant growth but 2+ dGH is a little low for
> > community tanks.  I would suggest 100 mg/l or ~5 dGH as a general
> > guideline and only go lower if your fish require it. 
> Many of our fish like neons, corys, otos and various algae eating
> catfish come from the Amazon basin. This tends to be a low oxygen,
> low alkalinity

Like I said, "go lower if your fish require it".

> For breeding, I understand, you want cold, very soft water.