Orca Aquacultural Laboratories Phospha-Guard BIO-Cubes use carbohydrates to remove phosphates to fuel a natural biomass combat phosphate vs. GFO and other systems that look to absorb it. Orca’s Phospha-Guard BIO-Cubes are a passive method that does not require a fluidized media reactor, just use a mesh filter bag and put in a filter or sump chamber and can easily replace GFO or other methods.
Orca mentions they use “…Redfield’s Ratio to remove phosphate naturally.” Simply put, Redfield’s Ratio is about mimicking the ratio of carbon, nitrogen and phosphate in phytoplankton. You’ll see this as C:N:P and numerically is 106:16:1. There are plenty of arguments about this vs. other methods, so we won’t get into that here, and we aren’t sure how the ratio itself removes phosphates, rather maybe the bacteria biomass is designed to keep phosphate low in appropriate numbers.
One point of differentiation they mention, that unlike the other carbon biopellets, Orca states Phospha-Guard BIO-Cubes is a point source treatment which prevents system crashes occurring. The biomass is also non-toxic and created by the heterotrophic bacteria that can also provide a source of nutrition for corals and other filter feeders.
However, if you’re interested in using these, they also note you should use their Nitra-Guard BIO-Cubes. Not sure if this is because it requires this source to create the bacteria first, or if its because it gets the nitrogen levels down to the required point first.
Orca Phospha-Guard BIO-Cubes are available in 250ml, 500ml and 1 liter containers. For low Phosphate levels (below 0.75ppm) add 0.5ml per liter and above 0.75ppm add 1ml per liter of aquarium water.