Algae growing with poor nutrients??

[Antoniocastro]

I have a problem
Film Green algae it’s growing on my tank mainly on rocks, I thought I had a problem with Po4 and No3 but my levels are:
Po4 = 0 ppm Redsea test
No3= 2.5ppm. Redsea test.
My Lps corals are unhappy and some sps frags are losing colors.

I added some Chaeto to my sump with lights
But after 2 weeks the Chaeto dies!
Then added an algae scrubber with the same light which I installed for Chaeto. After just 3 days the algae it’s growing very fast.

I don’t know what’s wrong maybe unbalance in No3 and Po4...?
Or I don’t know why test show me 0.?

Some signals says that I have poor nutrients system! (Chaeto dies, unhappy corals, test results).
But my rocks are covered by film green algae and algae scrubber it’s growing so fast!!

 

[nden]

Your tests are reading 0 because the algae is taking those nutrients.

 

[Antoniocastro]

Why do you think the Chaeto died?
And why the corals don’t take the nutrients too?

 

[Snookin]

Age of tank?

 

[Antoniocastro]

2 years