A potentially dumb question about param testing

[Theulli]

My calcium and alkalinity test kits both say to fill the syringe so that the black plunger is at the 1ML line, and that "a small bubble under the plunger will not affect results".

What is the definition of "a small bubble". When I use these syringes, it is approximately .1 ML (so the plunger is at 1mL, the liquid starts at .9).

Thanks!

 

[Jekyl]

My calcium and alkalinity test kits both say to fill the syringe so that the black plunger is at the 1ML line, and that "a small bubble under the plunger will not affect results".

What is the definition of "a small bubble". When I use these syringes, it is approximately .1 ML (so the plunger is at 1mL, the liquid starts at .9).

Thanks!

Just make sure the plunger starts all the way closed and suck without getting extra air. It's designed to have the same amount from the tip having air in it. Just follow the directions and don't worry about how much air is in there.

 

[Aquanic]

I'm assuming you're using a hannah checker of some kind. Recently I've noticed that sometimes the air bubble isn't always the same size in the syringe, so I took off the plastic part and make sure there is no air in the syringe as i draw it up to 1 ml. It makes me feel more certain that i am getting exactly 1 ml. It is kinda hard to get it with no bubbles, though.

 

[ReefEco]

i've run into the same issue - I just plunge the syringe full and empty a couple times, and the bubble usually goes away. You can certainly adjust your technique so there is no air bubble at all...

 

[Jekyl]

i've run into the same issue - I just plunge the syringe full and empty a couple times, and the bubble usually goes away. You can certainly adjust your technique so there is no air bubble at all...

You don't want the bubble to go away. The test results depend on that air being in the syringe.

 

[gbru316]

The "no bubble" thing is a result of medicine -- injecting an air bubble can have dire consequences.


Syringes meter based solely on the travel of the plunger. If you're using a syringe tip, there's going to be air between the liquid and plunger seal. This doesn't matter. Assuming you're starting with the plunger fully closed, you're only ever going to be able to dose what you draw into the syringe. And if you take the time to tip the syringe up and dispense the air bubble, you'll be left with an equivalent volume of whatever you're dosing left in the syringe when you're done. Which may or may not impact test results as that liquid will not be stored in a sealed container before the next use.

 

[Aquanic]

The "no bubble" thing is a result of medicine -- injecting an air bubble can have dire consequences.


Syringes meter based solely on the travel of the plunger. If you're using a syringe tip, there's going to be air between the liquid and plunger seal. This doesn't matter. Assuming you're starting with the plunger fully closed, you're only ever going to be able to dose what you draw into the syringe. And if you take the time to tip the syringe up and dispense the air bubble, you'll be left with an equivalent volume of whatever you're dosing left in the syringe when you're done. Which may or may not impact test results as that liquid will not be stored in a sealed container before the next use.

I guess the best remedy for this would be to rinse it out after a few times with RODI. The problem i was running into was that the seal between the syringe and and plastic end piece wasn't always airtight, and it was hard to tell when it leaked a little air or didn't draw as much as it should have. It being directly in the syringe lets me see exactly how much i have.

 

[mdb_talon]

I guess the best remedy for this would be to rinse it out after a few times with RODI. The problem i was running into was that the seal between the syringe and and plastic end piece wasn't always airtight, and it was hard to tell when it leaked a little air or didn't draw as much as it should have. It being directly in the syringe lets me see exactly how much i have.

I used to have that issue when i used hana alk checker that seal on the syringe tip seemed to often leak air in so i removed the tip also.

 

[gbru316]

I guess the best remedy for this would be to rinse it out after a few times with RODI. The problem i was running into was that the seal between the syringe and and plastic end piece wasn't always airtight, and it was hard to tell when it leaked a little air or didn't draw as much as it should have. It being directly in the syringe lets me see exactly how much i have.

Slow, gentle, and as parallel to the direction of plunger travel as possible. If that fails, time to replace the syringe.

 

[Theulli]

Thanks everyone, this is helpful!

 

[SharkRacer]

I just posted a similar question earlier today and got some great input that might help you:

How to use Salifert Alkalinity test kit? These videos suggest different methods.

I’ve been struggling a bit to up my game in terms of water testing and could use some help. The 2 videos below suggest different means of knowing how much to fill the syringe in the Salifert Alkalinity test kit. One video instructions matches the instructions that came with the kit, and...

www.reef2reef.com

 

[ReefEco]

You don't want the bubble to go away. The test results depend on that air being in the syringe.

If you are using the supplied large angled tip with the syringe that comes with some Hanna checkers, then yes - the space near the plunger will be equal to the volume of that tip - if that is the "air bubble" you are referring to. If you don't use the tip (i never do) then there should be NO air bubble at the plunger at all. I think that was the "small air bubble" the OP was referring to - not the space resulting from the use of the tip...