Trying to set up my hydroponics demo in my sun room

I am very new to hydroponics and can’t seem to figure this balance out. I am almost done with my first 2 greenhouses and set up a demo hydroponics system in my sun room. But the plants never grew to maturity and just wilted. I got a PPM meter and it said 3000 ppm with a PH at 6.5. But still nothing grew like others. I am not sure how to measure the need of fertilizer, calcium nitrate, epsom salt. Anyone willing to talk me back into this method?

This is the greenhouse that will be completed q3 of this year