The Squid
Spaced-out CephaloMOD
Yes for sure. I used one of those for a while until I forked over the cash for a really nice digital ph meter. No more worries for me there and I am so glad. Not to say you can't do it with the liquid drops. It's just hard or impossible to check runoff when its dirty and your water with nutrients in it. It changes the color. I remember someone on here saying that's all they use and they had plenty of rep points and grows so you never know. Just depends, there are always variables. Good luck dude.