hydro PH adjusting

Hello, I am just getting started with a flood and drain system. I have well water and the PH is at about 7. I do not have a PH meter yet Ive been using just the dropper and color match. when I use PH down to get to the optimum levels my PH goes right back up to the original readings 24 hours later. Does anyone know why? Thanks

That sounds normal to me. I have to adjust my PH daily.

There are a myriad of reasons for ph fluxuation. If there is any plant matter present, as it decomposes, it can cause things to acidify. The method you are using too test is also a bit sketchy. Here's my "tech-tip" of the week my brother. For 8 bucks you can get up on one of these digital ph meters, http://www.ebay.com/itm/Digital-PH-Meter-Tester-Water-LCD-Monitor-Pen-Aquarium-/160562316004?pt=LH_DefaultDomain_0&hash=item25624282e4. I've been using them for years, save yourself a ton of grief and get one now. When you have to re calibrate use cokacola, and calibrate it to 2.4. I't cheap, easy and there's no reason for you to not be doing this.

Try using white vinegar to get the Ph down. One cap per gallon of water well get it right around 6.3-6.5. Do a test gallon and check after a day or two. If it works then there's your easy fix

Thanks a lot guys, I went and purchased a digital ppm tester and PH tester today. Also got all new nutes, apparently the duffball that sold me the last ones sold me soil ones. So we start all over with new water, clean hoses and res. The nutes slimmed my system co if your new to hyrdro as I am then take my advice and get GOOD advice and save yourself a head ache and dead plants. My PH issue was to much air, I was running two 10 in air stones, well that and the WRONG nutes was too much for a 20 gallon res.
Hope all your grows are good!