Anyone know how these guys work?
Does the pumping mechanism actually come in contact with the fluid?
Do they back/forward siphon at all?
Anyone care to do some ml/min tests? (Specs say 3.5 gal/hr which is about 220 ml/min, but I’d like some real data)
Does the pumping mechanism actually come in contact with the fluid?no idea
Do they back/forward siphon at all?Im guessing you mean when the pump is turned off? Mine did not siphon when off.
Anyone care to do some ml/min tests?The rate is going to be directly related to the head pressure. Also, these are $15 pumps and are far from being precise. I have two that were bought at the same time the feed different rates in the same scenario. IME, they also can vary quite a bit. They are great utility pumps and have many uses, but precision dosing isnt one of them.
I agree with most of what Shawn said except mine does back flow when off
I used micro ballvalves on mine dialing the discharge back so that might have been the reason they never siphoned.
I use one for my ato and it works fine. It adds the water slowly and mine doesn’t back siphon.
[quote=“logans_daddy, post:2, topic:1835”]
Do they back/forward siphon at all?Im guessing you mean when the pump is turned off? Mine did not siphon when off.[/quote] Yes
Anyone care to do some ml/min tests?The rate is going to be directly related to the head pressure. Also, these are $15 pumps and are far from being precise. I have two that were bought at the same time the feed different rates in the same scenario. IME, they also can vary quite a bit. They are great utility pumps and have many uses, but precision dosing isnt one of them.
If rate is based on head (no doubt) that isn’t a problem at all, varying between pumps isn’t a problem either, variation between runs could be a problem depending on how severe. Do you have any more info on how much it varies? I’ve no doubt it varies based on how high you are pumping, but that would be pretty static, I wonder how much it varies based on the fluid height of what it is pumping out.
how much difference between the basic aqualifter and the dosing pump? both look to be 3 1/2 gph flow rate. didnt seem to be much difference between the two…
I couldn’t tell the difference either, they look about exactly the same…I’m guessing they just relabel it…
Okee dokie…quick look looks pretty good.
Anyone know how these guys work?Didn't take it apart, but it def sounds like a diaphragm just like an air pump.
Does the pumping mechanism actually come in contact with the fluid? Do they back/forward siphon at all?No/Yes, it didn't back siphon (maybe a little), but it definitely forward siphons, so the outlet end needs to be above the inlet end.
Anyone care to do some ml/min tests? (Specs say 3.5 gal/hr which is about 220 ml/min, but I'd like some real data)
I ran 4 sets of data w/ 3 or more data points at each setting, I kept the following settings the same and varied source height as that would be changing as the dose liquid was pumped out.
Destination height: 21"
Time: 5 seconds
Source height: 3", 5", 6", 7 3/4"
Heres the statistics, +3x and -3x are ± 3x of the standard deviation, statistically if I were to run that pump again in the same settings as the test there is a 99% chance I would get a data point in between those numbers.
3"
Average 9.5
+3x 11
-3x 8
5"
Average 10.16666667
+3x 11.89871747
-3x 8.434615859
6"
Average 10.6
+3x 11.85499004
-3x 9.34500996
7.75"
Average 9.833333333
+3x 10.69935874
-3x 8.96730793
Overall
Average 10.10714286
+3x 11.88961244
-3x 8.324673278
Basically all the data falls on top of each other based on measurement noise. I’ll try to get a more accurate beaker to get more accurate numbers, but looks like it doesn’t vary much at and is pretty repeatable.
Is it just me or do the numbers appear to be moving in the wrong direction as the source height increases?
Is that the height in the container or distance to the pump?
[quote=“Cdangel0, post:10, topic:1835”]
Is it just me or do the numbers appear to be moving in the wrong direction as the source height increases?
Is that the height in the container or distance to the pump?[/quote]
I was thinking that also but thought I was missing something. As the head pressure increased the flow should decrease ???
[quote=“Cdangel0, post:10, topic:1835”]
Is it just me or do the numbers appear to be moving in the wrong direction as the source height increases?
Is that the height in the container or distance to the pump?[/quote]
It is height in the container.
It is mostly variation in my readings, with that beaker I had a hard time telling the difference between 9-11 mls as the marking was only at 10 mls and hte next being at 20 1/4" away. I have a pipet with much better resolution and will retest. I chalk all the variation up to error in measurement.
[quote=“Cdangel0, post:10, topic:1835”]
Is it just me or do the numbers appear to be moving in the wrong direction as the source height increases?
Is that the height in the container or distance to the pump?[/quote]
Actually if you look at the first three (3", 5", 6") it SEEMS like the numbers are going in the correct direction, but the 7.75" data throws that off, but it’s all crap in the measurement noise.
Ok, here’s data with measurements with a bit more resolution.
Running at 1 second each, I only did 2 source heights as I assume the (if any) difference would be linear and not have curvature i.e. you could apply a simple y=mx+b slope to predict/compensate for it.
6"
Std. Dev 0.054772256
Average 1.65
+3x 1.814316767
-3x 1.485683233
3"
Std. Dev 0.054772256
Average 1.46
+3x 1.624316767
-3x 1.295683233
Overall
Std. Dev 0.112006493
Average 1.563636364
+3x 1.899655844
-3x 1.227616884
My conclusions. It does a little bit over the course of the source height changing, I assume this is linear and could implement a slope to compensate for it based on the dosing bottle, but…
Across 3" of difference in the source height I’ve got a 99% probability of getting w/ in 0.67 ml of my target and more likely w/ in 0.2 ml of my target.
For me that is more than adequate for dosing cal, alk, or mag and if you can cut or dilute your vodka (or carbon) in half or thirds it would acceptable.
Whatcha guys think?
I think there is a reason why people dont use these pumps for dosing. Also, i would NEVER in a million years put ANY form of carbohydrate on a doser, you would be just asking for trouble. Auto dosing the chems you propose is a very dangerous game. If your really serious about this method, i would really look into balling and balling salts. Its not too popular stateside, but you can get the equipment and chems from specialty vendors and UK online vendors. There is also a lot of DIY potential for this method. I was doing some reading on a translated german site where a guy actually mixes all of his salts and gives all of the “recipies”. Dont you work in the medical field? Maybe you can try getting your hand on some IV perilistic pumps. I know selling refurbed hosipital units was BIG business for a while.
I also think you need to brush up on your math ;D Im not sure what you mean by implementing a slope? Any changes in rate of a fluid is by definition non-linear and can not be described by a linear equation. A slope is exactly that, the rate between your two variables. If you really want to quantitize your results, i would suggest you stick with the stats. A regression equation or line of best fit might be what you were thinking of? Try getting a copy of Minitab, there are plenty of cracked copies our there if you know where to look. Its a very powerful stats calculator that will give you a much better picture of what your working with. Excel is ok for stats, but i would look into minitab…
[quote=“logans_daddy, post:16, topic:1835”]
I also think you need to brush up on your math ;D Im not sure what you mean by implementing a slope? Any changes in rate of a fluid is by definition non-linear and can not be described by a linear equation. A slope is exactly that, the rate between your two variables. If you really want to quantitize your results, i would suggest you stick with the stats. A regression equation or line of best fit might be what you were thinking of? Try getting a copy of Minitab, there are plenty of cracked copies our there if you know where to look. Its a very powerful stats calculator that will give you a much better picture of what your working with. Excel is ok for stats, but i would look into minitab…[/quote]
The effect of the difference between source height is linear or damn close to it, a ‘best fit line’ can then be a linear equation. ‘What I mean by implementing a slope’, is based on the data points drawn I can implement a best fit line to describe the output based on source height, which can be calculated from mls pumped out tracked by the controller. This best fit line can be linear.
I would do peristaltic pumps, but I can buy 3 of these for the price of one of those, if it works great.
Auto-dosing 2/3 part mixtures (calcium, alk, and mag) isn’t a very dangerous game. It doesn’t very much at all from your listed ‘balling’ method, except for balling takes into account trace elements and more expensive components. Thanks, but no thanks, out of the scope of what I am trying to complete here.
Who’s been peeing in the Cornflakes again?
OK - couple of thoughts here, and in no particular order.
Your measurments scare me a little as far as fluxuations. Regardless of how much liquid is in the source container (3", 5", 7") the flow rate should not be changing as you would be drawing from the bottom of the contaier in each situation - so your head height is not changing. The fact that you’re pumping mechanically not gravity fed I don’t think head pressure is going to come in to play. So in other words I don’t think the pump is accurate enough for dosing.
Can you run the tests a few more times to see if there are fluctuations in the results?
Also, given the incredibly short run time of the pump (mili-seconds) - is that enough time to get the liquid from the source container through the pump and on it’s way to the tank before the pump shuts off? I think you may find yourself watching the liquid moving up the source tube and just dropping right back down when the pump shuts off.
Cutting vodka with water (RODI or otherwise) will introduce bacteria that will begin eating at the carbon before you have the oportunity to dose your tank so you’ll never know the true concentration your dosing. If you check the TDS in your bucket of RO/DI after a day you’ll see it no longer reads zero because bacteria is colonizing, once it starts colonizing it will use the vodka as a food source.
I don’t know if that’s a bad thing or not though - isn’t the idea of dosing vodka to increase the bacteria population in the tank? is there that great a difference between growing the bacteria in the tank or in the vodka bottle? I guess your big concern would be the bacteria dying off in the vodka bottle and causing you to dose ammonia instead.
See? told you they were in no particular order. :scratch:
Well isn’t vodka diluted with distilled water anyway? Thats what I gathered with a little bit of research, but I’ve never made vodka before…yet 
AFA it changing due to the source container height. It is pumping out of the bottom but there is more pressure ‘helping’ it pump the higher the water column in the source container, for example 27.7 inches of water column is one psi of pressure.
The measurements were varying about 0.05 - 0.1 ml per run, that data set I provided is with 5 runs each at those two settings in varying order. Yes I can run the test more times and get tighter standard deviations.
AFA the bacteria consuming and adding the bacteria…Good points, I got no clue ???