I am afraid my tank may crash soon

[lost66]

I noticed my chaeto startring to die and GHA to grow in my DT. My tank is 2 years old and I have never had GHA. Recently saw my rocks little bit green and in couple of weeks a mesh of GHA. Few rocks have fully evolved GHA. My parameters are stable, phosphate is 0.11ppm, nitrate 0.4ppm.

Recent changes in my tank are:
1) My chaeto light died and I replaced it by something what states to be full spectrum and has the same wattage my old bulb has. The difference is the new one is white, old one was pink. I don't know much about light, have no idea if the color of light matters to chaeto

2) I had some reef chili so I broadcast feed few times

3) I had some amino acid so I decided to dose it - why not, right?

My understanding is that something happened and GHA is sucking up all food chaeto should consume to thrive and prevent GHA to grow. But I have no idea why and how to revert that process. I am unable to manually remove GHA, I tried to use metal brush but with no luck. Tank is not super polluted by GHA yet but I fear it may change soon and my tank will crash because I won't be able to keep it stable and corals will be covered by algae.

Please advise.

 

[Sean Clark]

Your 0.11 phosphate is very high given your 0.4 nitrate. I would try to get the po4 down and stable and maybe add a second light for your chaeto to help it overtake the GHA.

 

[Dkmoo]

Chaeto after a while dies from Iron deficiency so check your iron level and maybe start dosing chaetogro.

Alternatively, just plug out the gha and dump them in your fuge. This may be an unorthodox answer but my fuge grows gha and a lot of other kinds of algae. I've had the longest success with this methold of nutrient export compared to growing 1 specific kind of macro algae in my fuge.

I've always said "one more strand of GHA growing in the fuge is one less strand growing in the DT"