Nutrient mixing order?

(I just posted the same thread in General Growing Forums, but I realized this should be probably posted in here instead. Sorry and please delete my other thread if needed)

My plan was feeding 350ppm.

RO water measured 20ppm
I mixed in 4ml/L of Canna Rhizotonic and measured 100ppm.
I mixed in 1ml/L of Canna Coco A and measured 270ppm.
I mixed in 1ml/L of Canna Coco B and measured 350ppm.
Fixed PH to 5.8 and nutrient soup is ready now.

Next time I added exactly the same amount of same nutrients, but only in different order.

1ml/L Coco A - 200ppm
1ml/L Coco B - 270ppm
4ml/L Rhizotonic - 300ppm

How is this possible? One way I got in total of 350, but when I started with Coco A and B, then I got a weaker solution in the end.

Both ways I used exactly the same amount of water and accurately same amount of nutrients.

1) What should be the correct order when mixing together nutrients when I aim at certain ppm/EC level?

2) If feeding schedual (www.canna.com) says plants need 500ppm for example, does it mean 500ppm of Coco A and B or does it mean all nutrients together should sum up at 500ppm?

Canna Coco A and B, Rhizotonic, CannaBoost, Cannazym - these are the nutrients I am going to use.

Some strange kinda chemistry going on there

Did they both PH the same or did one need more than the other to balance?

I believe that the instructions are referring to the A&B at 500. It would only make sense to cap the whole mix at 500.

I figured out the problem! It was about shaking the nutrient bottles first. I forgot about it.

You say it would only make sense to cap the whole mix at 500. You mean all all, not only Coco A and B? The whole soup along with base nutes and additives?

Most nutrient bottles say to use more than actually needed. I've noticed that using half strength solutions work just as well and no risk of burning. The nutrient makers are running a business so using more= buying more.