First time hydro user, wilma

I'll be setting up my wilma soon once I've purchased my new greenqube tent, just wondering when you feed hydro you feed into the rez right and top up your "ppm" or what ever it is to a certain strength...
If your feeding your plants multiple different types of nutes, how do you know which ones your lacking in for example your using a root agent and something else, what if it hasn't absorbed all of one but more the other..??
Stupid question I don't know?
I guess that's why you change the whole Rez every couple off week?
I've done very little research so far in hydros so please exuse my ignorance.
Cheers.

Yes your on the right path there is no way to determine what the plants are using. Some people recommend topping off with PH water only. I think this is a good starting point if your new to hydro.
Here is some basic info for starting in hydro.

1. Get some good monitors to track PH,PPM, and Water temp.(I use blue lab three in one monitors but there is cheaper solutions)
   
2. Log these readings daily in a spread sheet or HERB IQ a free open source tool.
3. This will give you a good idea when to raise your ppm levels.
   
4. As water is depleted due to plant uptake and evaporation your PPM may rise, make sure to top off your reservoir to avoid the possibility of burning your girls.
   
5. Seedlings and clones start at 1/4 strength of the manufactures recommended dosage and go from there.
6. Try to stay with one strain per system as you can dial in their needs better.( I run two strains but they are related through breeding and the feeding schedule seems to work well for both.
7. add drip clean to your rez to help avoid clogs
   
8. cover exposed areas from light until your canopy shades those areas.

I hope you enjoy the process and continue to learn more as you go.

One more thing clean your system often when doing nutrient changes.

Awesome, that's pretty much everything i was asking and needed to know without completely overwhelming me lol.
Yeh I was going to purchase a tri-meter.
All I need to know now is feeding times, how long, how frequent, and when during veg and flower.
Was going to use clay pebbles and either make or buy some of them hydro hats or would you use them blue dripped things I've already got on the kit.

I run recirc DWC with top feed so my system runs 100% of the time. After looking in google images it appears your running a (very) similar set up just with less flexibility and plumbing. As my plants grow I can move them farther apart. You are limited by your size of the tray that sits above the res.
Based on the pictures I saw run your system all the time. Obviously your lights would still be on a timer for the photo period you are replicating flower or veg.
****( UPDATE FROM ORIGINAL POST ) ***
Ok I was on another forum I belong to and found a post on the wilma system.
I am not sure exactly how the system is supposed to work a cross between flood and drain and dwc recirc or just a different configuration of Flood and Drain?
Anyway here is quote from a post I came across.
"I've cut the feed schedule down so the wilma pump runs for 15 minutes every 4 hours."
***(END OF UPDATE)****
As for net pots...Don't use them if you don't have to.I like these options .