I not sure if you can compare them as one is type of system or filter and the other is or should are products. Salts and additives. I would say you should compare the Red Sea system with the Aquaforest, because with the Zeovit has the Nitrate Phos reducing system while the others do not. If you a just looking at Dollars I would have to say the Aquaforest would be the cheapest. I also believe that Tropic Marin has a system also.