I was at a spa store today and found a bottle ofLeisure Time Spa down intended to lower the ph levels of spas. It is 95% Sodium Bisulfate and 5% inert ingrediants. its not a liquid rather it is disolvable granules. Im wondering if this product will harm my plants or not? Honestly my plants have been growing about and inch an a half a day and my PH is at about 7. should i try and even lower it to 6.5 or so or can i leave it? doesn't seem to be affecting now, but i am less than a week in and don't know what to expect when the roots start growing more. Nearest hydroponics store is an hour away and have been trying to find something to lower my ph. any recomendations? THANKS!