Ppm and ph

So I'm trying to figure ph an ppm out what's the best ph and ppm for a fruity pebble strain an our city water is like 334ppm so I am hearing between 700 and 1400 so in way off If this is right but I'm trying to zone that part in thanks also .y soil is like 7.3 but I bought the mother earth brand soil

PPM isn’t hugely important in a soil grow, unless your water is terrible, which yours isn’t The soil ph is fine. For nutes, you could start at 1/2 or 3/4 of the manufacturers recommendations, and see how the plants do, then adjust accordingly. You want to PH your nute water to around 6.2. You may or may not have to add calmag, depending on what the 334 ppm’s in the water is made of. You should be able to get a breakdown of the ppm’s from your water supplier.