Slo-mo coral die off

[maxtek]

I treated GHA with hydrogen peroxide — removed the most impacted rocks and physically removed and then dripped a 3% hydrogen peroxide solution in the areas. I don’t think I rinsed them effectively. This was about two weeks ago, and it was quite a lot: four large rocks and two small ones. Since then, corals have been slowly dying off. I’ve lost three colonies so far, and this one is bleaching now.

I’ve been doing continuous water changes at a rate of 15% per week. Alk changes by no more than .1 per day. Temp and salinity are constant. Nitrates and phosphates are unmeasurable.

I’ve also switched to a more blue spectrum from my AP700s and increased the PAR slowly over the last few days.

What should I do to try and narrow down the problem? Could it still be the hydrogen peroxide?

 

[glb]

Can you pull the corals out and quarantine them until you figure it out?

 

[vetteguy53081]

What is your phosphate level and you can try LITTLE GFO to see it it breaks down hair algae.
By chance, is tank at or near a window?
Lawnmower blenny will help reduce as will astrea, turbo, nerite and nassarius snails

 

[maxtek]

What is your phosphate level and you can try LITTLE GFO to see it it breaks down hair algae.
By chance, is tank at or near a window?
Lawnmower blenny will help reduce as will astrea, turbo, nerite and nassarius snails

I have consistently measured 0 phosphates so I think the uptake is too quick for a measurable buildup. Tank is not near a window but is rimless... I am running carbon in case something toxic was introduced. I will also do an ICP test. I can try the GFO for a bit and see, but I also have an ARID and a fuge both of which are rapidly growing Chaeto, so I was hoping that would export phosphorus.

This morning, I noticed a whiff of fishy smell from the tank, together with an earthy smell that I usually associate with nitrates. Meanwhile, nitrates again measure 0 on the API kit. There have been no livestock deaths that I can tell.

 

[vetteguy53081]

I have consistently measured 0 phosphates so I think the uptake is too quick for a measurable buildup. Tank is not near a window but is rimless... I am running carbon in case something toxic was introduced. I will also do an ICP test. I can try the GFO for a bit and see, but I also have an ARID and a fuge both of which are rapidly growing Chaeto, so I was hoping that would export phosphorus.

This morning, I noticed a whiff of fishy smell from the tank, together with an earthy smell that I usually associate with nitrates. Meanwhile, nitrates again measure 0 on the API kit. There have been no livestock deaths that I can tell.

As I always recommend- A second opinion on readings. Take a water sample to a trusted LFS and have them compare with your readings and verify parameters. Although API kits are user friendly- not always spot on, so a second comparison is an assurance/Insurance