Chasing the impossible dream?

Dave asked if snails can carry fish parsites or diseases.  I know that snails
which are brought into the aquarium from outside sources can carry a parasite
which will kill a fish.  I can't remember the name of it but it has a very
weird life cycle including needing water fowl, snails and then fish as hosts.
 The fish dies....the duck eats the dead fish...snail eats duck
droppings....fish eats snail...fish dies......
I have a planted tank with discus.  After struggling for a while I found that
if I really packed the plants in the tank and provided good lighting I did
not have an algae problem.  I keep many discus in bare bottom tanks with only
two fish to each thirty gallon tank.  This tank is only 45 gallons and it
houses 6  discus nine month old fed three times a day.  I could not do this
when I had only a few plants in the tank.  The algae took over twice.  When I
planted nearly every inch of gravel with plants and put in some duckweed  my
biggest problem was seeing the discus.  Hope this helps.
Mary Sigman
Sigmanfam at aol_com