Daily variables in E.C and Ph and how to compensate?

Can anyone kindly help me?-What should my E.C. be in my nutrient tank and should I adjust the 'run-off' everyday with PLAIN water-The Ph and E.C seems to rise in the tank everyday and should I compensate for this(as above)?

 

Hmmmmm. For TDS in ppm (If I remember right 500xEC ~ TDS ppm) the veg value should be about 800 - 900 ppm (this is a safe value). The tank can have the pH adjusted with pH down directly however the contents should be totally changed once per week. The values will change as the plants use up the nutrients and there is not as much buffering (as with soil) so keep your meters handy.