Re: Red Algaes & Nitrates

> From: "Robert P. Ellis" <rpe9 at ix_netcom.com>
> Red algae, or Beard Algae, thrives in water where Nitrate and Ph 
> levels are too high.  But it would seem that nitrate is the key.  My tank had 
> been algae free for six months.  As soon as the Nitrate levels climbed over 
> 25, in came the beard algae.
Hmmm... I'm not sure I concur with this strategy of limiting Nitrogen. 
(other advice was fine) If you find that you are accumulating nitrates
in the tank, it is extremely probable that the other conditions are
not optimal in the tank. These include: sufficient light *intensity*,
sub-surface water circulation to promote CO2 absorption, CO2 concentration
and the presence of other required nutrients in the water and/or in
the substrate. Many plants also require a good growing medium in the
substrate (although "good" is hard to quantify ;-)

I have relatively high lighting levels and have found it difficult
to maintain adequate nitrogen & potassium levels in a primarily gravel
substrate even using solid plant fertilizer tablets (Jobe's Plant
Food Spikes) inserted under the substrate. Certain plants grew very
well when their roots had direct access to a piece of the plant stick
however, I am cautious about the use of these as it would be easy to
create a toxic situation by overdosing and by having insufficient Fe
levels (esp in the substrate) Last week I started on the PMDD regime
which introduces precise doses of nitrogen, potassium, iron and
several other nutrients daily. Already, there is immediate evidence
of improved growth rates on certain plants and visible greening of
new leaves. I anticipate less problems with K deficiency evident
in older leaves but its too soon to tell. Others have reported
dramatic improvements in reduction of algaes with the PMDD approach.
(of course with the other critical factors above)

Steve in Vancouver BC (where sunny weather is barely hanging in there)