Volume of a drop of R-0871


Gold Supporter
Jun 5, 2020
Camarillo, CA
I'm working my way through a SLAM; my CYA is 60, so I'm using a lot of R-0871 drops to do the FC tests. I came across a thread the other day saying that I shouldn't squeeze the bottle when dispensing drops. I think I was doing that too much to hurry the process, so my FC readings were initially indicating high (meaning my actual FC was too low). Is there a standard volume of a drop? Since I need 48 drops for a FC of 24, is there a number of mL I could measure to use instead of drops? Finally,, my bottle is about empty, once it is empty, could I refill it with water and experiment with that? Would a drop of water be the same size as a drop of R-0871?


Gold Supporter
TFP Guide
Jul 21, 2013
Northern NJ
The reagent bottles are designed for 24 drops per ml. The tip is designed to let the drop form and is the proper size when it naturally falls off the tip. You should hold the bottle vertical and let the drop form and fall off. Don’t squeeze the bottle to squirt drops out.
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Gold Supporter
Bronze Supporter
Nov 30, 2019
Pawleys Island, SC
The first drops will just fall but you have to squeeze the bottle after the first 2 or 3. Squeeze gently so as to only form a drop every 2 seconds or so to get a consistent and maximized droplet.
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