Red Algae Invasion

  We need some help to get rid off a red algae plage...

    -We have a 75 galons aquarium,
    -CO2 automatic controled system,
    -2 Philips-aquarele 36W fluorescent units.  
    -The Aquarium  is 1 year old.
    -Dual pump filtration system (30 Galon/h) 
       which came with the aquarium, and an extra punp 
       that only works during the light-time (12h).  
    -We change 1/4 of the water once per month. 
    -PH [6.9 .. 7.1]  ( 7.1 during the night, without CO2 system)
    -GH [8..12] ( 12 when we change the water, and 
        using resines is lowered downto 8)
    -Kh [5..9] ( 9 when we change the water)

  In order to fight that horrendous & terrible algae we
   have tried allmost everything:

     changed water, overfiltration, changed light-time ...

   Finaly we used an algae chemical controler called:

          Wardleys's ALLCLEAR II 
          which basically has something called 'Simazine '

  We put 0.14 oz (12 tablets) of this stuff ... This 
 ought to be enougth for a 60 galons tank. 

  As a result of this, 15 days later,  the red algae  
looks weaken, but also  other plants. Our AngelFish
look depressed ;-). 

  We changed the water (an 1/2 extra change this month),
 and plants and fish, look like are going back to  normallity 
(angelfish eat again!)... and so does the f*ck*ng red-algae  :-( 

  We identified our invasor was 'red algae' placing a pice 
of algae with alcohol, in a few minutes it became red. 
Boiling and keeping it inside and outside the water
for 2 days  did not make change it's color.

          Please, can any one help us with this stuff?

                                Ignacio & Vicente Gil

                      vgil at lander_es