What is Reddit's opinion of American Marine Pinpoint pH Monitor Package?

From 3.5 billion Reddit comments

Yeah even with more expensive ones you have to calibrate.

Also you never want the probe to dry out. Gotta keep it submerge in water to retain the memory.

I use this one. It comes with a little bottle that acts as a cap and keeps the probe submerge the whole time.

https://www.amazon.com/dp/B001EHAZ30?ref=ppx_pop_mob_ap_share

I use this one

American Marine Pinpoint pH Monitor Package https://www.amazon.com/dp/B001EHAZ30/ref=cm_sw_r_apanp_QBx1h7qaxnMpi

You can use a battery or power cord

Im not sure what you mean by the valve but is this what you had in mind? http://www.amazon.com/American-Marine-Pinpoint-Monitor-Package/dp/B001EHAZ30