Testing strips vs liquid test

[DavidW]

Hi, I'm in two minds about testing strips and I'm currently trying the JBL Proscan which I don't think is that accurate, it maybe I'm not using it correctly but it doesn't seem to read consistently. The guy I bought my tank off gave me a full liquid testing set it for marine but would it also work on freshwater?

 

[dw1305]

Hi all,

I'm in two minds about testing strips and I'm currently trying the JBL Proscan which I don't think is that accurate, it maybe I'm not using it correctly but it doesn't seem to read consistently.

There are very few test kits that give you reliable, repeatable results.

The guy I bought my tank off gave me a full liquid testing set it for marine but would it also work on freshwater?

Depends on the reagents it uses, because you have a known amount of chloride ions (Cl-) in sea water (about 17ppt ~ 17,000ppm) testing for mono-valent anions like NO3- is simplified.

I think testing is quite a problematic area, I think we would all like to know the composition of out tank water, but it just isn't possible with-out access to the type of analytical lab. you would get at a water utility company.

Have a look at this whole thread <"New High Tech Setup - ..."> for a bit more discussion.

cheers Darrel

 

[PARAGUAY]

All test kits have to be to phamacy standards,confusion seems to be when they use "hobby" as a description as they are aimed at professionals as well as hobbyists and designed to appeal to both.Practical Fishkeeping did Best on Test with all different kits and liqiud kits came out on top.Of course as Darrel indicates other factors affect accuracy of results. meaning some dismiss them .altogether not something PFK recommend ,I have the API mainly in case of concerns about fish health

 

[dw1305]

Hi all,

Practical Fishkeeping did Best on Test with all different kits and liquid kits came out on top

I would expect that generally semi-quantitative titrimetric methods (involving a colour change) would be better than testing strips.

All test kits have to be to pharmacy standards

I'm not saying that the producers of the test kits are charlatans, or that there isn't a standard scientific methodology behind each test.

We still use titrimetric methods for PO4--- analysis in soil and water, the result is read from a spectrophotometer (<"reading absorbance at a specific wavelength>"), but that is just a more objective way of judging colour.

The major problems are that you don't get a consistent result over a range of water conditions and there are <"quite a lot of decisions to make"> (pH, likely concentration, other elements present etc.) before selecting an appropriate technique and reagents.

If you had access to an <"Inductively coupled plasma mass spectrometer"> (ICP-MS) you could analyse the elemental composition of a water sample fairly easily, but these are huge amounts of money to buy and run.

cheers Darrel

 

[Paulo Soares]

If you may:

For some two years i test and test brands like Sera, Nutrafin, Amtra, and others.

Last year i decide to bought JBL KNO3 + PO4 + K + FE + MG.

So, as mentioned here sometimes even me got different values doing tests one after another.
Why?
Cause we dont´follow specific reccomendations. And they are truly important.
For instance the inclination (diagonal / vertical) of the reagent bottle is very important to reach always the same volume drops so the drops to be equal as much as we can in the mixture. Different volume of the reagent drops will give you different results.

Same appliance to the spoon that come along with powder reagent test. We need really filled the greater or the smaller part of the spoon.

Always emerge the glass bottles where we test in the tank and let it be for some couple of minutes.
After testing i put all glasses in a tupperware filled of water and insert in my microwave for good cleaning and after with paper toilets to dry and really remove all remainings of powder left in the bottles.

About JBL and other brands:

According to what i said before about procedures of JBL testing, i took some water of my tank and give it to a friend of mine that works in the City Hall Water Department LAB and after she analised the water i could conclude that JBL Liquid tests are truly reliable and with a little margin of error.

As for me i dont´buy any other brand than JBL and i do trust in the liquid test kits results. Specially the NO3 and MG where the margin error was almost zero.

Big hug to all.

 

[DavidW]

I've not tried the JBL liquid tests, but the proscan testing strips gave me some strange results. I did one test and looked at the results and thought that can be right, so I did another test straight away and some results were very different so I did a 3rd test and the results were different again.

I could have been doing something wrong. Just don't know what I did the same process each time started the timer on the app dipped the strip for 3 seconds waited for the app to count down to 0 then took a picture of the strip against the reader card background and the app pops up the results.

From the results I got the PH seemed to be fairly accurate and close to what my ph pen was reading the GH and KH were all over the place as was the Nitrate level one test was 25 the next was 75 then 30.

 

[alto]

One of the US Reef sites ran an experiment with various sourced test kits, some newly purchased, some brought by the participants - so this included out of date unopened kits, opened in date kits ...
each participant ran the tests with each kit, all tests done in at least duplicate (by each participant)

Result: the main source of error was human error 😀
(all of the kits gave much the same results ie none of the reagents had "gone off" even on the expired kits BUT all of the reagent solutions also appeared normal; in general it's best to use kits that are in good date & have been opened for <1 year, it just removes that possibility of error)

(samples were prepared so known results)

I use both liquid & test strips, don't see significant differences with the results, I get similar results with each repeat test
(but I have technical training 😳 )


If you're not good at reading the charts (color perception) or measuring sample volumes (again this will often impact color observed), results can vary dramatically
Due to costs & what customers expect to pay, kits have changed over the years - you're not likely to find a kit with included test compound "standard" (eg nitrate solution of known composition which acts as a positive "control" for kit reagents & customer technique) or laminated card color chart, extra sample vials etc

With test strips it's import to not touch any reagent block with fingers, or allow tank water to "run" or drip between reagent blocks, strip must be emersed long enough to properly "wet" reagent blocks but not so long that reagent diffuses away from the test block, when strip is removed from tank water, it needs to be held at an angle & "blotted" to remove excess tank water (but not blotted too much or not enough sample remains for "test") - some manufacturers are much better at test strip chemistry/product quality BUT these companies are generally selling to the technical market as these are rather higher cost/price per strip (look at water analysis or medical test strip supplies - these test strips provide excellent "fast" data that is generally very accurate & reproducible)

Test strips are also much more susceptible to improper storage (never leave container open as moisture will often partially "react" test block reagents) & it's important to only touch the single strip that you will be using.

From the results I got the PH seemed to be fairly accurate and close to what my ph pen was reading the GH and KH were all over the place as was the Nitrate level one test was 25 the next was 75 then 30

full liquid testing set it for marine

Buy the freshwater version & see if your results improve.
Some kits reagents/chemistries are different for saltwater vs freshwater testing

 

[DavidW]

I've not used the saltwater test kit, the buy I bought the trigon 350 off just gave it to me with the tank. The results I was getting were from the test strips.

I'm wondering now if the app is affected by light levels, after you drip the test strip and the app counts down you take a photo on the test strip colour card. Is it possible if the light changes it would give different readings?

 

[alto]

😳 I though the test strip were also saltwater version but it seems they are only available in a freshwater version

From JBL

Why do I get different measurement results with repeated measurements?


Please note that the analysis strips will continue to react. Thus a strip can only be scanned once. A repeated scan would lead to different values, because they change dramatically after 70+ seconds. However the fluctuations can also indicate an incorrect reading caused by shadows/reflections. It is best to carry out the test near a window with bright light and using a sheet of white paper as a matt non-reflecting base. Direct light from above casts shadows or reflections which can affect the colour rendering. The ColorCard should be uniformly illuminated. Please remember to ALWAYS shake the water sideways off the analysis strip. “Puddles” can cause the colour fields to react with each other and to produce reflections. Please always approach your smartphone vertically to the ColorCard.

More clues here

Why don’t the water values match my JBL drop count test?


Each test has a fixed scale, which enables the allocation of the water values. For example the steps in a drop test are different to those of the ProScan. Therefore ProScan also has a scale to enter the values and to avoid jumps at repeated measurements. Bigger differences between the values mostly indicate an incorrect reading caused by shades/reflections. Best is to carry out the test near a window with bright light. Direct light from above casts shadows or reflections which can affect the colour rendering. Please remember ALWAYS to shake the water off the analysis strip sideways. “Puddles” can cause the colour fields to react with each other and to produce reflections.
Incorrect values can occur through expired drop tests too (i.e. tests which have been open for more than 9 months) or incorrect use (with air-filled drops and deviating water quantities). In this case please check your measurements once more.

One example:
The aquarium has the following water values: 18 mg/l NO3, 0.5 mg/l NO2, 5° dGH, 7 mg/l CO2, 1.5° dKH, 6.8 pH.

The measurements with the different systems give the following values:
The ProScan shows following values: 18 mg/l NO3, 0.5 mg/l NO2, > 4° dGH, < 15 mg/l CO2 (by way of calculation), 1.5° dKH, 6.8 pH.
The drop test shows the following values: 20 mg/l NO3, 0.6 mg/l NO2, 5° dGH, 10 mg/l CO2 (by way of calculation), 2°dKH, 6.8 pH

Both results are very precise and differ only slightly from each other. This has no negative effect on further statements and actions. Inaccuracies in the application have a greater effect on the results than jumps resulting from the scale. Finer scaling steps could result in an inability to allocate the results exactly to the same measuring points when there is some divergence of light and distance in the surroundings. This would cause the values to jump again in a repeated test.

I think you've found the error in the system 😉

Given the price I'd be inclined to request a demo at the sale shop, also email JBL & complain (perhaps they'll send you a replacement set of test strips ... )
- seems JBL did not think this system out quite so clearly 😵
JBL Website is nicely done & they seem interested in product support

​

 

[ian_m]

According to what i said before about procedures of JBL testing, i took some water of my tank and give it to a friend of mine that works in the City Hall Water Department LAB and after she analised the water i could conclude that JBL Liquid tests are truly reliable and with a little margin of error.

Fail.

You have not stated what analysis method they used, most likely as they test tap water using exactly the same type of test strips or liquid test reagents that JBL use, therefore would get exactly the same wrong reading when used with tank water. Using test strips & solutions for testing tap water is probably fine due to the complete lack of fish water tank contaminants that influence test strip results.

Testing for nitrate levels is an extremely complicated process that when using tank water which is why you cannot get reliable & repeatable results. Please see DW1305 posts above for why this is so.

 

[alto]

I've yet to see an Analytical Test lab that uses test strips exclusively for water reports, they may be used as quick onsite guides, but most analyses are performed by rather more complicated machinery/technology ...
It's highly unlikely that any Analytical Test Lab would be using JBL type reagents, everything in a Testing Laboratory is documented & must meet GMP & ISO standards etc

Using test strips & solutions for testing tap water is probably fine due to the complete lack of fish water tank contaminants that influence test strip results.

Try to imagine the level of complex contaminants in Urine - test strips are routinely used in Urinalysis with a certain percentage of "normal" samples sent on for more complex testing (basic QC), any "out of range" samples are confirmed with alternate test methodologies.
Test strip chemistry like kit chemistry is well researched & documented analyses, while there are some questionable products on the market, this is true of any testing method including pH/TDS pens & assorted ion specific electrodes.

Nitrate testing is not rocket science by any means, slightly more complex than GH/KH etc but nothing particularly complicated 🙂
- major consideration is type of water conditioner used, though even this tends to be very temporary (ie don't test directly after water change), if you've just added fertilizers etc, wait for complete "mixing" through the water column before sampling.

Paulo Soares gave some excellent tips

 

[dw1305]

Hi all,

Nitrate testing is not rocket science by any means, slightly more complex than GH/KH etc but nothing particularly complicated. Major consideration is type of water conditioner used, though even this tends to be very temporary (ie don't test directly after water change), if you've just added fertilizers etc, wait for complete "mixing" through the water column before sampling.

That is pretty much it.

I'm not saying every-ones test kit results are wrong, in fact I'm happy that a lot of people are getting figures that are at least in the right ball-park. A person maybe able to get repeatable and accurate values (across a range of parameters), especially if they have some experience of the scientific method.

If @alto tells me that they had ~10ppm NO3 (ideally a mean and related confidence interval) I would be confident that they do.
The problem comes because their readings may not be comparable with some-body else's 10ppm NO3, particularly if one person has high conductivity, alkaline water, and the other person has soft, acidic water.

If two people, with very different water parameters, have large healthy dark green Amazon Frogbit plants, I can tell both of them straight away that they have plenty of nitrogen available, what-ever the results of their test kit shows.

cheers Darrel

 

[jameson_uk]

I've not tried the JBL liquid tests, but the proscan testing strips gave me some strange results. I did one test and looked at the results and thought that can be right, so I did another test straight away and some results were very different so I did a 3rd test and the results were different again.

I could have been doing something wrong. Just don't know what I did the same process each time started the timer on the app dipped the strip for 3 seconds waited for the app to count down to 0 then took a picture of the strip against the reader card background and the app pops up the results.

From the results I got the PH seemed to be fairly accurate and close to what my ph pen was reading the GH and KH were all over the place as was the Nitrate level one test was 25 the next was 75 then 30.

I bought some of these today as I am colour blind and find the API tests difficult to read. Also figured that if I need the in-laws to look after the tank whilst I am away that these might be easy enough for them to use.

Did exactly what it said to do and got the readings but these didn't bear any correlation to those from the API kit and redoing the measurements from the same strip multiple times (even under exactly the same lighting) was giving me massive variations.

Nitrates were 0 then 25
GH went from <3 to >7
CO2 from 35 to <15
pH was 6.8 then 7 (API says it is 7.4)

The API kit was saying 10-20ppm Nitrate (nearer 20)
pH is nearly always 7.4
GH is almost a constant 12

Got the wife to try on her iPhone to rule out my phone / Android but she got different results to me. In fact taking different readings from the same strip I got Nitrates reading anything from 0 to 60 (mainly 0) but I suspect the API kit is probably more accurate.

I have ordered the Salifert Nitrate test (as it looks like this might be colour blind friendly too) so later in the week I will try this, the API and the JBL strips to compare.

 

[Paulo Soares]

Fail.

You have not stated what analysis method they used, most likely as they test tap water using exactly the same type of test strips or liquid test reagents that JBL use, therefore would get exactly the same wrong reading when used with tank water. Using test strips & solutions for testing tap water is probably fine due to the complete lack of fish water tank contaminants that influence test strip results.

Testing for nitrate levels is an extremely complicated process that when using tank water which is why you cannot get reliable & repeatable results. Please see DW1305 posts above for why this is so.

In other words you´re saying that the Department is fooling around with public Health...

I rest my case.

 

[zozo]

In other words you´re saying that the Department is fooling around with public Health...

I rest my case.

I know a few examples of scandals in that direction, from my own country.. 🙂 ( 🙁 ) I live about a 25 kilometers from a rather large worldwide known chemical industrial complex, called DSM. Now this stands for Dutch State Mines and it started out as one of the biggest mining companies in the country funded by the state department since 1902. Next to mining it did also do lot of chemical research and material development, productions and major brakethrough inventions in that direction famous all over the world.

DSM produced tons of building and other industrial materials containing asbestos, these products were put in roof panels, pipes, briks, clothing, cable insulation, heating insulation, only to call a (very) few. You don't want to know how much of this stuff is still around you today.. Especialy when you live in large cities with all those wonderfull historical buildings. Since asbestos was already used for many centuries for it's physical properties it is around us in abundancy, but rather swept under the carpet and burket. Somewhere around 1900 there already were suspicions that this stuff causes major health problems, also burket and not officialy investigated because of the economical consequenses involved. It took till around the later 1980's it became officialy known and asbestos was officialy recognized as a health hazard material to work with. Probably triggerd by the mining industry where it was used in abundancy and the investigation of all those 1000nds early deaths of retired miners after serving 30 years undergound. All dying the same suspicious death..

Suddenly around mid 1990s some investigators dug up some official labtest fact sheets deep within the DSM archives dating back to 1970.. Where DSM researchers reported to the authorities about the health hazard involved with working with asbestos without proper protection.

Catch my drift? In 1900 suspicions, in 1970 official reports presented to the authorities, in late 1980 baned from certain producton lines.. And mean while the world is still full of it.

There are a few more..

I think yes you can rest your case.. We don't want to know.. 😉

On the other hand we are still on this planet, actualy overpopulated. Who knows maybe in a 10.000 years we are alll purple with little green flourescent freckles and leave a slime trail behind when we move around.. 😵 As long as we keep our hands to work with, the authoreties probably don't mind so much..

 

[Nelson]

we are alll purple with little green flourescent freckles and leave a slime trail behind when we move around.. 😵

Marcel,you need to leave them mushrooms alone 😉.

 

[zozo]

I only smoke a sigar once in a while and drink some beer.. It must be in there... 😱

Actualy the bartender always asks me, why do you always look at your wifes picture after finishing a pint? But you know, after every pint, she gets more beautiful and when she's beautiful enough, i go home..

It must be in there.. Hops??

 

[Nelson]

Actualy the bartender always asks me, why do you always look at your wifes picture after finishing a pint? But you know, after every pint, she gets more beautiful and when she's beautiful enough, i go home..

.
Can't believe you just said that 😱.I think it's called beer goggles 🙄.

It must be in there.. Hops??

No,tap water 😉.

 

[zozo]

Stop it.. You are scaring the fish...