Re: Algea in the undergravel filter (on purpose)

"So it does sound reasonable that one would be able to limit the algea
growth
to just the area where I want it to be?  The only reason why I would
shy
away from just trying this would because of the fear that the algea
would
end up spreading to the rest of the tank.

Anybody have experience with an algal scrubber (which is what this
basically
is).  Does the algea have a tendency of spreading to the rest of the
tank,
or is it happy staying where you want it to be?

Thanks,
Harry"

I used several designs for algal scrubbing in FW tanks.
As far as something to export nutrients (the only reason one would
find to use the darn things) plants are far more effective at export
than algae are.

If you are going to use one, they require more light than plants for
the similar nutrient export. The algae on the bottom of the tank will
evwentually rot, decay as it builds up and this will no longer help.
You need to export the excess nutrients somehow for this to work well
over the long term.

You also need to assume excess nutrients cause algae in planted tanks.
That's a _big_ assumption. NH4 perhaps, but the others are not a
problem if you have enough plant mass/decent growth.

Planted tank is the goal is it not? Should you focus on healthy plant
growth rather than nutrient exports? The less algae the better.

Aquatic plants require more nutrients than algae and more PO4.
I have seen numerous research papers to this effect as well as growing
plants for many years and the pattern clearly shows this.

Try the plant filter, you'll have much more success.

Regards, 
Tom Barr