white layers at the surface of the cleaned dry rocks

[Oscar_H]

Hi all!
I am starting saltwater aquarium and have question regarding the cleaning of live rock and dead corrals (which I was thinking to use as a live rock). So, I washed both dead corrals and rocks with a bleach solution followed by washing with water. after that I left it to dry. When I eventually added rocks into aquarium I noticed that water was not crystal clear anymore and the concertation of phosphates was elevated.
After washing of the rocks and dead corals, I have noticed some white layers at the surface and now I am wondering if it maybe slowly dissolve in the water causing the problem.
Does anyone know what this white layer can be and how to clean it in case this is causing the problem?

Thankful for any suggestion, I am very new in this.

p.s.- I am attaching the photo of the corral with the white layer

 

[ndrwater]

Looks like a normal coral skeleton to me. Corals can have different densities based on conditions when the coral was growing. Elevated phosphate is quite normal for a tank with freshly cleaned rock. You can either let it be... It will continue to leach for quite a while, or .. add some GFO. Granular ferric oxide absorbes phosphate. It is best used in a reactor. YouTube has many videos about setting up and properly using a GFO reactor.