p7willm
Active Member
I just got a scale to weigh .01g, https://www.amazon.com/gp/product/B0012LOQUQ/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1, and a magnetic stirrer, https://sraquaristik.com/product/speed-test/ and I love them both.
The scale is more accurate, especially when I do it quickly, than the 10 ml syringe for measuring 5 and 10 ml. When I need the 16 and 17 ml it is even more accurate since I have the error from 2 readings on the syringe and only 1 for the scale. The scale reads in .01 and is accurate to +- .02g and a drop of water weighs about .04g.
The stirrer makes it much easier to mix the reagents in. Drop the magnetic pill in and turn it on and then just drop the stuff in and it mixes. As opposed to drop the stuff in and swirl the bottle gently, being careful not to swirl too much and spill and not swirl too lightly and not mix well.
When titrating it is even better than the Red Sea holder for the bottle with the attached syringe. Start the stirrer and just drip into the bottle.
When I do the titration tests I put the bottle in the stirrer and put the stirrer on the scale and push the button to zero. I fill the syringe and do not have to worry about getting exactly 1 ml of stuff. Turn on the stirrer and drip into it. Pay attention to the color and don't worry about swirling. When it changes color look at the scale and read the ammount you added. No squinting at the syringe and doing the hard math, subtraction makes my head hurt. the number is right there.
There are inaccuracies with the weight. The reagents do not have a SG of 1, it is within my margin of error measuring out 1 ml since, being real careful and taking far longer with the magnifying goggles, the weight jumped around quite a bit and I am do not think the syringe is accurate enough to get a true 1 ml sample. The scale is +- .02g but a drop of water is .04g and i had errors with the syringe of .05. The kit is also a little questionable.
All in all I might not be getting the exact correct values but I am getting more consistent numbers than before and I think a consistent number that is off by about the same amount every test is better than bouncing around the correct number.
For around twice the money, a whole $20, you can get a .001g scale but that is probably overkill. In order to use it correctly you are going to have to shield it from breezes, the little puffs of air inside you house can easily be weighed on the scale, and protect it from vibration, your significant other walking in the next room will show up. It is also more delicate so it would be easier to break. It couldn't be easier to use. Flip open the cover, which protects the scale when you are not using it, and press on. Put the bottle on and hit tare to zero the scale and add water until you get what you want. If you are titrating hit tare to zero again and titrate and when you are done read the result. Don't forget to get a calibration weight, about $6, cause you need to calibrate it and test it occasionally. Don't tough the weight cause finger prints have weight and the acid from your body will corrode the weight and throw it off.
The stirrer is built to hold the bottles Red Sea uses for their tests and comes with one, I am sure you can find additional on the web. It runs on a 9 volt battery and I have no idea how long it lasts yet. It is small and light enough to fit on the scale so you can do your titration on the scale. When I got it the speed control was horrible but twisting the nob a few times fixed it and not it is just bad. On the other hand I don't think it matters if it is spinning at 440 or 520 rpm. It is real simple. Pop off a door on the bottom for the battery, an on/off switch on the top, a knob to control speed, and a "holder" for the bottle. You can not use larger bottles cause the holder would keep it from getting close enough but smaller would work if you held them and got a smaller pill to stir them. I think there is going to be a similar one with a built in light. This might be nice to have, especially if you want to test at night on a camping trip, but there is more than enough light to see the color change and the holder has a large area cut out for when you want to see a small amount. The pill is teflon coated so it should be easy to clean along with the bottles. There is only 1 included but I have ordered a pack of 10 for $15, I also got a teflon coated magnet to pick the pill out of a bottle because it looked cool and cost $15.
Neither of these things is "laboratory" grade but in some respects they are better for what I want, and a lot cheaper. I have looked around and there is stuff available for thousands of dollars that will tell me if I have 440 or 443 calcium but that is not what I need, the stuff looks real cool, but this stuff is cool enough.
Any questions?
The scale is more accurate, especially when I do it quickly, than the 10 ml syringe for measuring 5 and 10 ml. When I need the 16 and 17 ml it is even more accurate since I have the error from 2 readings on the syringe and only 1 for the scale. The scale reads in .01 and is accurate to +- .02g and a drop of water weighs about .04g.
The stirrer makes it much easier to mix the reagents in. Drop the magnetic pill in and turn it on and then just drop the stuff in and it mixes. As opposed to drop the stuff in and swirl the bottle gently, being careful not to swirl too much and spill and not swirl too lightly and not mix well.
When titrating it is even better than the Red Sea holder for the bottle with the attached syringe. Start the stirrer and just drip into the bottle.
When I do the titration tests I put the bottle in the stirrer and put the stirrer on the scale and push the button to zero. I fill the syringe and do not have to worry about getting exactly 1 ml of stuff. Turn on the stirrer and drip into it. Pay attention to the color and don't worry about swirling. When it changes color look at the scale and read the ammount you added. No squinting at the syringe and doing the hard math, subtraction makes my head hurt. the number is right there.
There are inaccuracies with the weight. The reagents do not have a SG of 1, it is within my margin of error measuring out 1 ml since, being real careful and taking far longer with the magnifying goggles, the weight jumped around quite a bit and I am do not think the syringe is accurate enough to get a true 1 ml sample. The scale is +- .02g but a drop of water is .04g and i had errors with the syringe of .05. The kit is also a little questionable.
All in all I might not be getting the exact correct values but I am getting more consistent numbers than before and I think a consistent number that is off by about the same amount every test is better than bouncing around the correct number.
For around twice the money, a whole $20, you can get a .001g scale but that is probably overkill. In order to use it correctly you are going to have to shield it from breezes, the little puffs of air inside you house can easily be weighed on the scale, and protect it from vibration, your significant other walking in the next room will show up. It is also more delicate so it would be easier to break. It couldn't be easier to use. Flip open the cover, which protects the scale when you are not using it, and press on. Put the bottle on and hit tare to zero the scale and add water until you get what you want. If you are titrating hit tare to zero again and titrate and when you are done read the result. Don't forget to get a calibration weight, about $6, cause you need to calibrate it and test it occasionally. Don't tough the weight cause finger prints have weight and the acid from your body will corrode the weight and throw it off.
The stirrer is built to hold the bottles Red Sea uses for their tests and comes with one, I am sure you can find additional on the web. It runs on a 9 volt battery and I have no idea how long it lasts yet. It is small and light enough to fit on the scale so you can do your titration on the scale. When I got it the speed control was horrible but twisting the nob a few times fixed it and not it is just bad. On the other hand I don't think it matters if it is spinning at 440 or 520 rpm. It is real simple. Pop off a door on the bottom for the battery, an on/off switch on the top, a knob to control speed, and a "holder" for the bottle. You can not use larger bottles cause the holder would keep it from getting close enough but smaller would work if you held them and got a smaller pill to stir them. I think there is going to be a similar one with a built in light. This might be nice to have, especially if you want to test at night on a camping trip, but there is more than enough light to see the color change and the holder has a large area cut out for when you want to see a small amount. The pill is teflon coated so it should be easy to clean along with the bottles. There is only 1 included but I have ordered a pack of 10 for $15, I also got a teflon coated magnet to pick the pill out of a bottle because it looked cool and cost $15.
Neither of these things is "laboratory" grade but in some respects they are better for what I want, and a lot cheaper. I have looked around and there is stuff available for thousands of dollars that will tell me if I have 440 or 443 calcium but that is not what I need, the stuff looks real cool, but this stuff is cool enough.
Any questions?
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