# How many drops in a ml? Small scale water dechlorinator?



## Jane in Upton

Hi,

I finally opened a new bottle of Prime dechlorinator water conditioner. It says to use 5 ml for 50 gallons. So, I assume that would mean use 1 ml for 10 gallons. But, how many drops to use for ONE gallon? 

I've rough estimated from the old conditioner. It said use 5 ml for 10 gallons, or 10 drops for 1 gallon. Therefore, the new stuff (Prime) is 5x stronger than this stuff (which used 5 ml, rather than 1 ml for 10 gallons). Therefore, should I use 1/5th the amount per gallon, or 2 drops?

I've thought about this every which way to the point that I'm really confused. I should revisit this in the morning, when I have my coffee supplemented brain in gear - my evening brain doesn't work the way it used to, LOL!
-Jane


----------



## littleguy

I had the same problem. You have a few options:

1. Get a medicine dropper somewhere (e.g. pharmacy), or an empty bottle that has a dropper built into the lid (e.g. a used up bottle of another dechlorinator brand). Then count the number of drops to fill a teaspoon, do some math and now you know how many drops in a teaspoon. I would hesitate to give my own calibration number, since I don't think all drops are created equal - I think the volume of a "drop" is somewhat dependent upon the dispenser. 10 of my drops might equal 6 of yours, for example.

2. Some of the small sizes of Prime bottles now have a dropper built into the lid, and the instructions say to use two drops per gallon of tapwater. Since this stuff is so concentrated, even the smallest bottles treat enough water to last me for years. Again, not all drops are created equal and I wouldn't necessarily use this figure if you're using your own dropper.

Hope this helps.


----------



## littleguy

Oh and by the way,

1 US teaspoon = 4.92892161 ml


----------



## littleguy

One more thing, I noticed that a lot of the pharmacy droppers make larger drops, and with less precision, than the droppers built into the lids of aquarium products. So if you have a dropper lid and bottle, I'd use that instead of a medicine dropper.


----------



## dennis

Absolutely! You should calibrate your dropper against a known amount. Measuring spoons, (though I usually don't trust them) test kit test tubes, syringes, etc all make good choices. Many droppers have a 1ml line on them and you could probably find one of those at the drug store.

Prime is pretty strong and whatever dose they tell you to use is *probably sufficient unless you have horrible water. If your on Boston's reservoir system, they don't use heavy chlorine and no chloramine, IIRC from talking with the director. Also, usign more dechlor than necessary wont hurt anything either, within reason of course. So, if you need 1ml and you use .8 or 1.2 it should not matter. Remember, a 10 gallon is only 8.5 gallons anyway but we don't worry about that. +/- a couple drops should not matter.


----------



## DataGuru

Get a syringe. That makes it easy to measure small amounts.


----------



## Cassie

technically, there are 15 drops in a mL, 5 mLs in a tsp, 15mLs (3tsp) in a TBSP...

those are the calculations we use for medical math at least, but, as mentioned before, it all depends on the dispenser, but I do use the 15 drops=1ml in dosing my tank using a medical syringe


----------



## Laith

DataGuru said:


> Get a syringe. That makes it easy to measure small amounts.


I agree this is the best solution.


----------



## Cassie

if you for some reason have a problem with getting a syringe, let me know, I can send one to you...


----------



## hoppycalif

Back when I was working in hydraulics we used 20 drops in one ml. The fluid we used was pretty close to water in density and viscosity, so I still use 20 drops to a ml when I estimate.


----------



## Teeleton

littleguy said:


> Oh and by the way,
> 
> 1 US teaspoon = 4.92892161 ml


So if you dilute it with 4 parts water, then you can add teaspoons where it calls for ml.

Teeleton


----------



## Squawkbert

Or count how many drops you can fit in a level teaspoon, divide that by 5, you have your number of drops per mL (usually ~20 in my experience).


----------



## littleguy

Prime's built-in dropper equates to 20 drops per mL as well... which means 2 drops of Prime treat 1 gallon of tapwater.

I agree with Dennis... if you're off by +/- 20% in your calculation it probably won't make a difference. If it were me, I wouldn't bother hunting down any special equipment. Dechlorination shouldn't be the most complicated part of keeping aquaria .


----------



## Jimbo205

My small bottle of Prime at work says to use 2 drops per gallon. I hope this helps.


----------



## Jane in Upton

Wow, thanks for all the great responses!

I've found a source for inexpensive measured pipettes/bulb dropper thingys, which I'll probably get for some of my plant things, anyhow. 

In the mean time, I've cleaned up the bottle from the old dechlorinator, and will test its drop size to a teaspoon just to satisfy my own curiosity. My guess is that I'll come out to using 2 drops per gallon. 

I really like the idea of diluting it with 1:4 water, then using tsp in lieu of ml - definitely a keeper idea!

Thanks again for all the great ideas and input!
-Jane


----------



## argblarg

Walgreens has syringes in the pharmacy for free if you ask for them. Many different sizes. I got some 5 ml ones which are perfect to use for test kits, and I use a 1 ml one for small water changes with Prime.


----------



## redstrat

I agree 20 drops per ml is normally a good estimate, you could just let the water sit out for 2 days or so with an air stone to dechlorinate. A syringe would be the most accurate though, I have a 3mL syringe that is graduated to pretty small incriments, drugstores like CVS have them. You should need 0.1ml dechlorinator per gallon.


----------



## DataGuru

2 days with an airstone won't gas off chloramine.


----------



## BryceM

Ask for an insulin syringe. Diabetics use millions of them so they're available almost everywhere. They make a 1ml variety that is very nice for smaller doses.


----------



## Burks

guaiac_boy said:


> Ask for an insulin syringe. Diabetics use millions of them so they're available almost everywhere. They make a 1ml variety that is very nice for smaller doses.


Those things rocks. Rather easy to get unless your state has strict syringe laws.


----------



## Jimbo205

In New York State anyone can ask for a package of 10 insulin syringes at any pharmacy without a prescription (cost roughly $2.00). For more than that, you will need a prescription. Each state may vary.

Very handy for dosing precisely in very small quantities for Nanos. 
1 Unit = 0.01 mL (in the U.S.) As others have commented, you may want to be discreet using them to avoid attracting unwanted attention. The caps are BRIGHT orange.

If you know of a diabetic or medical person that trusts you, they may give you their used ones for free. It is easier to dose if they are NOT clipped. On the other hand, sharps accidents can be prevented when they ARE clipped. Keep both in mind.

When you are done using them, be considerate of the staff that pick up your garbage and throw them out in a puncture proof container (Beach Bottle) or something similar. Or give them to a pharmacist or medical person to dispose of them for you.

If you do have a sharps accident (get stuck) with a syringe, contact someone with medical training for advice. Please be careful of the tips.


----------



## BryceM

I'd absolutely NOT recommend recycling used syringes under any circumstances. The small but real risk of transmitting a blood-borne infection just isn't worth the $0.10 cost of the silly thing.


----------



## Jimbo205

Typo: Bleach Bottle.


----------



## Jane in Upton

Well, I called my local pharmacy here in Mass. The insulin syringes they have do have needles, and the pharmacist said she didn't think they could be removed. She offered to get in some "dosing" syringes, so I've got 10 of the 1 ml and 10 of the 5 ml ones arriving soon. I'd rather NOT have the ones with sharp needles, seeing as (A) I'm a clutz and (B) what with reading all of the info on the diseased fish thread recently, I make a point of not putting hands or arms into the tanks if I have any wounds, like from my friend's kittens getting TOO excited about the toys I brought them. 

In the meantime, with the drop-measuring, I've been using 2 drops of Prime per gallon, and it seems fine.

-Jane


----------



## Kelley

Hey Jane,
I have plenty of the needle-free kind. PM me if you need a few.


----------



## laelw2000

*source of syringes*

I work at a veterinarians. We sell all sizes of syringes. No perscription needed. I use one to dose excel in my 1.5 gallon beta tank. It's a 6 ml dosing syringe with a cap, so I can even store the excel in the syringe. I use one drop per day.


----------



## Jane in Upton

Hey, thanks Kelley - I already asked the pharmacist to get them for me, and they're right up the street, so I'll follow through with that. What a kind offer!

And laelw, that hadn't occured to me - that I could just keep the syringe full of prime, and use it to dose AND store. I wonder if its adversely affected by light - the bottle it comes in is opaque. Well, with a small enough quantity in teh syringe, it probably would get used up faster than it decomposed, even if it is an issue.

-Jane


----------



## Squawkbert

A note on syringe usage (accuracy)

Draw up more than is needed, aim skyward, knock any air bubbles loose, dispense the excess & air while still pointed up until the top ring of the rubber seal is up to the volume desired (not the pointy tip of the plunger). Now you can dispense your intended volume.

I offer this instruction as a result of being an analytical chemist in shock at how many Bachelors level chemists show up in labs w/ no skills in the practical matters of handling labware. 

To those of you who already knew how to do this, please resist the urge to take offense...


----------



## primal

I can attest to the fact that the dropper can have a big impact on how many drops are in 1 mL. Just Friday in my chem lab we calibrated pipettes, and mine turned out to be 57 drops per mL. I think it also depends on the liquid you are dealing with (we were using pentane). It would be much more accurate, I think, to use those small syringes rather than trying to count drops. At least this way you won't have a problem with different liquids having different sized drops.


----------



## Jimbo205

2 Things I have learned about Seachem Excel & Syringes: 

1. If you pre-dose syringes too far ahead of time (I was trying to save time later) and it gets clogged - Just put it in a small cup of water and soak it for a short bit. You can add the Excel with the small amount of water.

2. BE VERY, VERY, VERY, VERY, VERY careful with overdosing Seachem Excel. 
I think it is like parachuting. It is the development of familarity and overconfidence that kills. 

I believe Seachem Excel is the only fert that can kill if it is overdosed. I may be wrong. 
I just don't want this to happen to anyone else. I like happy Bettas. 

I feel guilty about what I did to my old Betta. (Yeah, I know it's only a fish, but I liked him.)


----------



## Left C

I bought two of the 50 ml bottles of Prime to use for my small tanks. When I run out in a bottle, I add more from a larger bottle. 

2 drops for each US gallon or 4L is enough for each. It's good stuff!


----------



## JERP

The squeeze dropper included with my Flourish has a 0.5ml and 1ml marking on the side of it. It is very difficult to see if you're not looking for it, but it's there.


----------

