I ran out of my red pH indicator solution from my TF-100 kit. I have a crappy kit that was provided from the PB that has a bottle of pH indicator solution. Both the TF-100 and other kit bottles say the solution is 'phenol red'. Is all phenol red the same or is it possibly a different strength from the other kit. I could just take both kits out to the pool but I'd rather just put the full bottle of phenol red from the other kit into the TF-100 box. I ask because the mixing chamber in the other kit seems a lot larger than the one in the TF-100 so 5 drops would dilute more in the other kit. But perhaps the color shades on the sides are just calibrated accordingly.
Any thoughts? I know I could just order refills, but I'm lazy and cheap.