Sera Nitrite test kits

[[d]3v|L]

hi got the sera nitrite test kits recently at aquamart. got a problem. instruction says add 5 ml of tank water, then add 5 drops of reagent 1 and 2. after adding it into my water sample. colour din change and remained yellow (the colour of the liquid reagents). Why like that? waited for 1 hour oso nothing happen. When i tried with my other paper test kits, i detected nitrite, y?

[derf]

oops!! er... i wun reccomend sera test kits!!!! get salifert instead but remember to ask for the english instruction manual...

[[d]3v|L]

the sera got english instructions.. waste money buy another 1 for wat..

[bawater]

for the sera nirite kit- u need to x3 the result to get total value.(its in small print at the bottom of the box)

just gauging by colour, u have a rough guide on water conditions.

if its yellow- ok, if its orange then something is wrong with your filtration.

u only need to wait 5mins max for the results-in fact 2mins is enough.

The sera kit i use for freshwater.

[[d]3v|L]

wat u mean by x3? see nth under the box except for foreign language. after leaving it covered for more than 1.5 hour its still yellow. does it means no nitrite?

[derf]

the reason y i reccomend other test kits is becos sera's kits are pretty confusing. i've sera NO3 test kit at hm too but i gave up on it.

[clowntrigger]

just to add, if you think Salifert test kit is high on prices, you could try Tetra NO3 test kit. The color code is very distinctive, it range from yellow->orange->light red-> darker red, unlike Salifert, it still show different shade of pink

[derf]

erm... tho it's onli diff shades of pink, i find it the most accurate n easiest to read.

[clowntrigger]

well maybe I find myself color blind to pink, always find that the different shades are quite close well having say that, I have just started using the Salifert test kit, infact only once, hopefully with more practice, I am able to distinguish the PINK.

[derf]

the thing abt charts using diff color, eg, yellow to orange, is that sometimes u get colors that are 'inbetween' two diff colors. nw that really is confusing.

[[d]3v|L]

so... which is the best.

[wedgee]

Is there any testkit which doesnt use silly color differences to get the values? I'm using a Aquamedi dKH tester, and it uses the number of drops added, to get the actual value of the dKH (u know when it changes color)!!!

Now that is a better way of telling! Anyone know such a system for NO3 testkits?

[Tanzy]

Alkalinity is easy to detect because what you are seeing is the change in pH as you neutralise the solution. A good pH indicator can be choosen.

For nitrates you are not doing a titration but using your eye as a colorimeter based on the fact that intensity of colour is proportional to concentration. It is too expensive to produce a titration testkit for nitrates for use by amateur reefers.

Coming back to accuracy, how accurate in reality is the alkalinity testkits anyway? The drop size can vary and the volume of each drop only allows it to be accurate to 1 dKH. If you want to improve accuracy, you can use a spectrometer to measure the colour of the solution, but then you will have to think about how accurate the volume measurements are. <_<