In soil you want to be careful with baking soda as Ph UP because too much will build up bad salts in your soil. In soil, if you dont flush every once in a while it will throw off your entire soil ph and be hard to fix. In hydro or coco you can easily flush out salt buildups biweekly Vinegar is a great and CHEAP ph down solution. You can get 1L for a dollar and will last you a good while. My honest opinion is that companies will rip off growers any chance they can, just to make a penny. I personally use baking soda and vinegar with no problem, and I get the huge box/bottle from 99cent store. soda/vinegar= $2 every 3months bottled ph up/down= $10-20 every 3mo depending on consumption.