this is the recipe to follow, but was wondering if its safe to use tap water since its added to the tank. we have a TDS reading around ~700ppm here, so I was wondering if you could use RO or RO/DI?

and is Kent's Essential Elements needed? i was going to use RO or RO/DI water and the Miracle Grow to start off with

Starter culture from someone (even DT's would work, I've been told)
Tap water mixed to 1.019 sg
5 ml Miracle Grow Houseplant liquid food, per bottle, per batch
1 ml Kent's Essential Elements

Lighting 16 hours of light, 8 hours of darkness regulated with a timer
Steady bubbling of air via rigid tubing to the base of the bottle
Shaken slightly each day to stir up the solution from the bottom