Arduino? - PPM -EC | Co2 Meter?

Let me start with saying without being rude Please do not reply with negativity such as "You are a beginner, not gonna happen etc" Because I am sick of being told i can't do something due to knowledge then i research for 2 months and pull it off anyway. I am here to learn and for information most of you started in the same boat.

Now that's out of the way i wanted to make a Meter for my Job with Hydroponics and i wanted to create my own Self uploading and monitoring equipment. Simple Features as (Water's: PPM Maybe (EC in future) and PH) as well as Co2 Monitor for an environment Kind of how this guy did here by uploading the results to a cloud

Example: CJMCU-8118 (CCS811 and HDC1080) - ThingSpeak IoT

My Questions:
I just need to be pointed in the right direction for starters. For those of you once in my shoes thanks for your advice/input.

First and for most to save everyone time and effort's i just wanted to know what device should i be looking into for a 24hr running device example: Raspi, Arduino, Other? as far as most options to build on and work with for the task i require i can post examples of the pieces of equipment's tasks i am trying to replicate.

Reason For interest:

Some of the pieces of equipment created and sold for combined controllers are priced starting $3k+ (Cannot Afford, For multiple locations)

Datadecimal:
Let me start with saying without being rude Please do not reply with negativity such as "You are a beginner, not gonna happen etc" Because I am sick of being told i can't do something due to knowledge then i research for 2 months and pull it off anyway. I am here to learn and for information most of you started in the same boat.

You don't have to make it that obvious you're new here. That's what your post count gives away already.

PPM sensor: that's measured through EC, so you got that the wrong way around. Sounds simple, is simple, is not easy at all. I hope to launch my Kickstarter campaign in September for an inexpensive EC sensor, limited range but more than enough for hydroponics. Or if you like to build yourself - follow the links to source & schematics.

For accurate measurements you must add a water temperature sensor - the EC changes by about 2% for every 1 °C temperature change.

pH sensor: get an industrial type pH probe (those are designed to be continuously submerged) and amplifier board. Also can do with temperature correction.

CO2 sensor: no direct experience; a quick search here or on Google will tell you all you need to know.

Controller: as you want Internet connectivity go for an ESP8266 based board such as NodeMCU or WeMOS D1.

For CO2, use an NDIR type. It's essentially a small photometer with a filter so it only looks at the carbonyl peak, so it's very selective for just CO2. I've used several, and the K30 is very good. I also have used the Gravity and Vernier NDIR sensors. Unfortunately they are expensive, but they don't wear out, and other gasses don't interfere as they do with the resistive type