Phosphates in rock and sand

[Keith Russell]

So I really couldn't find anything that would help me so if I am repeating, i
I'm sorry. My stylo and frogspawn started to look awful like overnight. I tested my pars and found my phosphates were over 10.0. I did a 50% water change in the 40 gallon tank yesterday. I tested again today and still over 10.0 ppm. all other chemistry is good. dkh is a little high at 12, but all else ok. I'm wondering if the phosphates are in my rock and sand and if so, how can I fix this in a tank as small as mine without damaging the livestock?

Thank you so much for any help on this.

Dkh-12
Cal-400
ph-8.1
Nitrates-2
Am-0
Nitrites-0
Phos-10.0+

 

[Saltyreef]

You can reduce the phosphates further by adding some nitrate.
Your nutrients are wildly imbalanced.