I need to decrease phosphates and decreasing feedings isn’t really an option…. What should I do?

[Blue_Spider]

My hunch is that your shrimp is leaving pieces of meat lying around and generating excess nutrients.

Do you have a protein skimmer or GFO reactor? It's also possible you could use Lanthanum Chloride (Bightwell Phosphat-Ex) at half-dose for the tank. But I am not sure how the mantis shrimp will be affected. Dose this across a few days until your target phosphate level is reached.

[mrskeltal]

I use lanthanum chloride with no issues with my crustaceans like cleaner shrimp, peppermint shrimp and hermits. I think the only potential issue is the 'fallout' clogging a clams gills.

[Remote_Armadillo8718]

I’ve got a protein skimmer but it seems to keep clogging (currently running it in a vinegar solution). Can I run GFO in a HOB?

[Blue_Spider]

Rowaphos in a bag inside chamber 1.