We all know that in most cases feeding your skimmer from outside will increase your PH due to less CO2 being infused into your water. It is also generally known that the inlet should be protected / filtered to prevent any of the other nasties (fert, smoke, herbicide) from getting into the inlet. I have seen a few DIY methods, but wanted to know if anyone has seen one these used from Amazon? They are rather cheap and look like I can change out the carbon while providing low resistance to flow.
iPower 4 inch Air Carbon
iPower 4 inch Air Carbon