Is 1 Ml Equal To 1 Drop?

[Captain Retardo]

Is 1 milliliter equal to 1 drop?

I am going to fishless cycle my tank and it says to add 4-5 DROPS per 10 gallons

Please answer quickly!

 

[millym]

the amount of liquid in a drop depends on the size of the hole in the dropper! so no 1 drop does not necessarily equal 1mL. but if its ammonia youre adding to start a fishless cycle you should be measuring the ammonia levels with a test kit until they reach a spike ( see pinned topics on fishless cycles for more help) so the exact amount that you will get in your drops is not really critical.
does that make sense???

 

[Tolak]

The size of the drop depends on the viscosity of the liquid, not the size of the hole. A drop of water is the same size coming out of an eyedropper as it is coming out of a garden hose. A drop of heavy gear lube is much larger than a drop of water.

18 to 20 drops = 1ml of liquid the approximate viscosity of water. Ammonia is close enogh to the viscosity of water to use that as an estimate. The concentration of ammonia differs from brand to brand, and quite possibly from batch to batch of the same brand, so a test kit is needed. Once you figure out how much to add per gallon from the same bottle, you will be adding the same amount once it starts converting ammo.

 

[dwarfgourami]

It is still an excellent idea to be counting the drops so you know how much to add next time.

 

[Captain Retardo]

Thanks!

I answered my question a couple minute later when I found out I could actually do drops with my syringe!

I have a test kit (API Master test kit, its a good one!) and according to it it takes 200 drops of my ammonia to get a Ammonia reading of 5 ppm!

 

[Bignose]

The size of the drop depends on the viscosity of the liquid, not the size of the hole.

Mostly right (you didn't think I'd let a fluid mechanics topic sneak away without inputting something, did ya?).

It is a viscous instability that causes drop formation, but the diameter of the originial pipe is the initial condition. That is, it takes longer for the instability to break apart the constant stream into drop for a much larger diameter flow. Longer typically means that the center of the flow is moving faster, so more of the center will fill up, so you get larger drops.

There is also surface tension that can be a very large factor in drop size. the ratio of the viscosity to momentum (also known as the Reynolds number) and the ratio of viscosity to surface tension forces (also known as the Weber number) are some of the critical number needed to predict drop size and shape.

Plus, the larger the pipe, the more satellite drops you get. Satellite drops are the very very small ones you see, like the very tiny drop that comes up in that slow-motion video of a drop hitting a pool of water.

Finally, there are some fluids that just won't form drops. Some of the really heavy polymers you can actually cut with scissors, and even some of those have such a high surface tension that if you didn't cut them you could pour them out 10 feet or more and they still get sucked back into the cup.

All that aside, I got a medicinal eyedropper when I did my fishless cycle. It should have marks on it for every 0.1 of a mL so you can get acurate measurements without having to count 200 drops.

 

[Tolak]

Ah, thought you might "drop" in with a scientific explanation. I know it was bad, couldn't resist.

I have a few different droppers, from graduated ml dropper to the mother of all droppers, a turkey baster. The one I use the most is either a plain dropper, or a graduated 3 ml kids medicine dropper.