My school spends around $4000 for devices that can provide all these measurements, but I think an Arduino based solution is probable
Here are the kits/sensors I have found for this, mostly from Atlas:
TMP: Page has moved or https://www.atlas-scientific.com/product_pages/sensors/env-tmp.html
pH: https://www.atlas-scientific.com/product_pages/kits/ph-kit.html
DO: https://www.atlas-scientific.com/product_pages/kits/do-kit.html
EC: https://www.atlas-scientific.com/product_pages/kits/ec-kit.html
My question is:
Would one Arduino suffice for a project like this?
and subsequently:
Which Arduino?
and also:
What kind of circuit (generally) would allow for something like this? I'm thinking of output to an LCD that can be switched between modes (TMP, pH, DO, EC)
I am a beginner but I have been waiting for an idea for a big project and this seems perfect.