Normally we would not recommend the usage of chemical Nitrate and Phosphate remover as they will take out of the marine water the main nutrients which macroalgae will need to grow, eg Nitrate & Phosphate.
This said it might be sometimes necessary to reduce very high Nitrate & Phosphate concentrations in the marine aquarium / planted reef tank to avoid any damage to livestock, especially hard corals and/or to get the balance between Nitrate & Phosphate for an optimal macroalgae growth right, which we will explain more below.
As Nitrate & Phosphate remover often take out as well other minerals/trace elements which are necessary for some macroalgae species to grow we recommend to dose a fertiliser formulated for the planted reef tank / macroalgae tank when necessary.
Suitable fertiliser for the marine aquarium you can find which you can find HERE
Macroalgae for the marine aquarium are already of course a great way to naturally remove nutrients like Phosphate & Nitrate from the marine aquarium water by consuming them whilst growing, creating a more clean water aquarium environment.
As macroalgae will consume much more Nitrate than Phosphate it is for an optimal macroalgae growth recommended to maintain a ratio between Nitrate & Phosphate in the marine aquarium / planted reef tank between 20:1 to 100:1.
Which means that when you have for example a Nitrate level of 2 ppm the phosphate level should be 0,02 ppm.
It is as well recommended to keep for an optimal macroalgae growth a nitrate concentration of at least 2 ppm and a minimum phosphate concentration of 0.02 ppm, as otherwise the macroalgae may starve and potentially die off.