What should my ppm be?

I am about 1 week into my DWC grow. I started with a nute mixture at 380ppm I just got a meter and took a reading and it read 850ppm. The meter is calibrated properly. Is this normal, will the ppm increase over time? I am going to change the water in the tank tonight. I was going to mix up a nute solution at 500ppm dose this sound right? Also, I currently have the water level up to the bottom of the rockwool cubes. Since the plants are growing well and the roots should be growing should I lower the water level?

As for me I keep my veg ppm at around 800-900 and flower 1100-1200. As the water gets used the ferts sit at the bottom always stir before use and always check ppm because it can go up as the water goes down.

Oh I start my nute mix at 200 ppm for the first few weeks. I go slow so afraid of burn.

Yea man ur ppm will rise if you dont top off your reservoir. Makes the nute to water ratio rise leaving you with a higher ppm.

Thanks for the info. What about my water level should I keep it right at the bottom of the rockwool?

always check ppm levels.your ppm should drop if they r good feeding plant.when u r doing dwc u can get away with feeding them high i mean week1 500 ppm then week2 750ppm then week3 1000ppm week4 1250ppm thats vegie.now flower.week1 1250ppm week21500ppm week3 1750ppm week4 1750ppm week5 1750 week6 1750 week7 1100ppm week8 100ppm this low reading in the last week in flower is to wash the salts of the roots as plain water is not good as the 100ppm reading just add a wee bit of the flower nutes to get the 100ppm on the last week.this is a heavy feed only give this to plants that r healthy .the best thing to do is look up to see what feeds that your plant can handel as different plant like different feeds.the next inportant thing is the ph this has to be bang on or u will get nute lock out which can result in low yields.in vegg keep the ph at 6 all the way thro vegg then drop ph to 5.2 week 1 and 2 then keep the ph at 6 all the way to the end and see what great results u get.............all the best garry........................

Thanks for the great info Scottish Farmer. Let me ask you this. It is week 2. If my ppm is currently 850 could I just add so me water and bring it down 100 or so instead of changing the water in the tank? Or do I need to change the water every week?