RO water use

Subject: Re: RO water use

> In a message dated 96-04-05, Karen A Randall wrote:
> >IMO, the only buffering system that makes sense in the planted
> >aquarium is the carbonate buffering system.  In my experience a
> >the other pH adjusters are bad news.  At best, they make you fe
> >good because you have the pH where you want it and aren't reall
> >doing anything positive for the plants, at worst, they casue 
> >problems.  Using RO water, a reliable reconstitution product an
> >even a yeast based CO2 system, you should be able to put the pH
> >anywhere you want it.
> Please elaborate on this. I too, use RO water in my planted aqau
> however I haven't had any problems with PH swings. What do you r
> carbonate buffering? I have angels and tetras that prefer a low 

WILD Angels and some Tetras come from areas of very soft water, 
but even in those areas the water is not as free of minerals as RO 
water. (assuming that your unit is functioning properly)  Both 
plants and fish _need_ certain amounts of various minerals in the 
water... not just those that contribute to KH, BTW.  RO water 
should _always_ either be reconstituted with a commercial product, 
or mixed with tap water to reach KH/GH levels that are 

DOMESTIC Angels are routinely bred, raised and live long happy 
lives in moderately hard water with a pH above neutral.  They are 
very adaptable.  Likewise, even those Tetras that come from very 
soft water, (and many do not) will adapt readily to higher 
hardness/pH levels, although it is unlikely that they will spawn 
successfully in this type of water.  Considering that in the 
average community tank, most if not all eggs of scatter spawners 
(most Tetras) will be eaten, spawing is not usually a priority.  I 
have healthy Rummynose and Cardinal Tetras living in moderately 
hard water with a pH near 8.  They have been in that tank for over 
4 years now.

Karen Randall
Aquatic Gardeners Assoc.
Boston, MA