Algae eater problems

Subject: Algae eater problems

> I'm having problems with algae growth and what I find to be  the
> efforts of 6 algae eating fish to control it.

<Snip long description>

> The otos and pleco spend a lot
> resting on leaves and the bottom (maybe they do more at night). 
> expecting too much out of them? Could they be stressed into inac
> something? With the nitrate levels as low as they are, I would t
> wouldn't be much of a problem. Is there too much light, perhaps?

You are expecting too much of your algae eaters.  Algae control is 
_mostly_ your job, and the algae eaters are a useful adjunct.  You 
would not see the Otos and Pleco doing much during the day aanyway 
since they are more active at night. (particularly the pleco)

You don't have "too much" light, but it's too much for a taank 
with a very rich substrate, hard water and no supplemental CO2.  
Without the CO2 supplementation, the plants, even though they seem 
to be growing pretty well, cannot use all the nutrients that leach 
from the soil in your tank.  In the presence of your strong 
lighting, the algae is taking advantage of all that good stuff.

I suspect another problem which might raise its head to haunt you 
eventually if you keep going as you are is a dropping KH and 
consequent larger and larger pH swings as your plants try to meet 
their carbon needs through biogenic decalcification.

You have two options.  First, you can cut your light (probably in 
half) and live without some of the more light hungry plants.  Or 
you can supplement with an adequate supply of CO2.  On a 55G tank, 
that probably means at least two yeast reactors changed 
alternately and religiously every couple of weeks.  An easier 
solution would be pressurized gas.

Karen Randall
Aquatic Gardeners Assoc.
Boston, MA