PH issues

I am using well water. I would prefer RO water but that's not in the cards just yet. The well water is neutral. about 200ppm. When I run straight water I have no issues. They seemed to thrive well. Then, I added a half dose of Jungle juice micro/grow to be safe and "test the water" as it were, to be sure the well water won't stack with a full dose of nutrients and burn my babies 500 ppm total in early veg. My PH went through the roof. I am running 10 gallons through a unconventional system. Kind of a NFT/Drip/EF set up.

Nutrient film pump is always running. Then every half hour a drip line turns on and runs water over the roots and in turn floods the PVC tube for half an hour. Then shuts off, chamber drains and neutrient film keeps running a small trickle over the bottom. I ended up with this set up after being given hand me down parts.

Anyway, back to my problem. I read that PH up or down should be added in small doses. I have no PH meter as I ordered a cheap one online and got it so cheaply because its being shipped from China and won't be here foe 6 to 8 weeks... SO I am using liquid test drops. One that came with the PH up/down and another that was from an old fish tank set up. Both are reading a PH of 8+. I added 1 ML of PH down for 10 gal. Checked a few hours later. Nothing... Added 2 ML of PH down and let it dissolve over night. Next morning. Nothing changed. Plants stopped growing...

Added 4 more drops and a few hours later it was below 4... So I drained the reservoir. Flushed for 2 days with just 200ppm well water and they came back to life. Did the math on suggested nutrients to water ratio. added 50% of recommended for a general application. a very mild dose.

PH shot back up to 8+...

I see myself as fairly intelligent. Ive grown before but always in pots. soil less mix and never had any major issues. I want to learn how to hydro and I am realizing I know nothing. But I am willing to learn.

My next idea is to go to the store and buy some RO water... Then try to budget in a RO unit.

Any ideas? Feedback?

Just realized I posted in the wrong area. My apologies.

It is a good idea to mix your solutions in a separate container and then balance it out there before adding it to your plants reservoir. PH is tricky. a little goes a long way but you may have added something that threw it way off. Be patient. Add a little. Test it. You might be feeling rushed because the mix you are adjusting is running over your plants and its like working on live wires, You can easily screw up badly. Get another tote and an air pump/air stone and that way you can be patient with it and not burn your plants. Document what you add. You will eventually have the numbers you need. Then you have to do it all again when adjusting for flowering... Have fun and good luck.