Help with Auto top off and dosage system

[tcmike64]

I currently have a 300 FOWLR system. Unfortunetly my apt was flooded (not due to my tank) and I need to replace about 2-3 feet of sheetrock around the whole perimeter of my apt. My question is this, I have room in a closet which is about 25 to 30 ft away from my tank, and I wanted to run tubing or pipes (whichever I should) behind the walls, from the closet into my sump to create an auto dosing/top off system. What are your recommendations on how I should accomplish this. Since I need to top off water almost every other day, I wanted to create a system where I just had to fill up the water in my closet and it would take care of the rest. I also wanted to have a system in which it doses my system with for example (calcium/nutriets) with the recommended doses daily. All help is much apprecaited

 

[inline6]

You might want to try
http://www.aquahub.com/store/index.html
They have some float switches you might want to look in to.