Help with my ph please

So both my ph digital testers crap out on me today. I order 2 more but i wont get them till a week . I use r/o water i know that when it's r/o it's about 7ph . Using floranova grow when i feed and r/o with cal mag the next time i feed it water. My plants are about 10 inches plants some bushy. What can i do to keep them alive till then they all need water now and im trying to see what i can do . ? Any help thanks.

PS . Using Earth juice to ph my water

do the same thing you did the week before.
your nutrient solution buffers the pH, after "X" amount of days you pH down to get in Range again.
or
You can just run your R/O water if your unsure of your self. it's only a week right.

The thing about hydro is consistence.
You start with good water you know the pH ,and PPM
you add your nutrients you know what they buffer your nutrient solution to
after 3-4 days your pH rebounds. You add the same amount of pH down every week.
You run the system for 7-10 days, clean everything good.
--Repeat--Week--after--week-- until your done--
You should be able to run your system week after week like this, not even using a pH meter or TDS meter.

Good Luck on Your Grow.

I took the ph tester i had apart. put new wires and re soldier everything . My r/0 shows as 8ph now so am guess it;s 1.0 more up since it should be 7. But it's going down fine when i add ph down so hopeful that will do for now. I'm trying to hit 6.8-7.2 in my ph tester lol >.< The real ph it will be 5.8-6.2

I would calibar it but it hould be at 7 when i put in in my r/o and i dont want it to then go back to 7 out of no were because it has before.


And thank you for the advice.

Get away from pens they suck man get yourself a good combo meter esp when you have to check everything constently