Arduino controlled nutrient controller and pump system

I need a complete system capable of monitoring nutrient (using EC) and pH levels, making adjustments to nutrient levels and pH; by removing excess solution and adding low EC solution of equal volumes if EC values are too high, or adding nutrient solution if the EC is too low, adding an acidic/alkaline solution if pH is too high/low using parastalic pumps. The target EC and pH should be variable using a simple led/lcd screen interface and buttons, the EC and pH should be measured using attached sensors at set intivals and the readings should be logged in a database which can be exported to a computer. The margin of error needs to be low for recording and administering nutrient/pH values and there needs to be safeguards to prevent errors from adding too much/little solutions. Current EC pH levels should be displayed on the screen as well as simple error messages. There needs to be 2 tones/sounds that are activated for either correct functioning or for errors. The system should be pre connected and tested including the microprocessor, display unit, EC and pH sensors and parastilic pumps. Low error margins for sensor readings and amount of pumped solution is key. There needs to be about 6 to 8 parastilic pumps for the range of functions 2 for adding/removing set amounts of solution in high EC, 2-4 pumps for adding nutrient solution in low EC, 2 pumps for adding acid/alkaline solution to balance pH. 2 meters of industrial acid/alkaline resistant tubing attached to each pump would be great but not compulsory. A wooden mounting board and plastic housing for the system would also great but not compulsory.