Api Test Kits.

[robyngunston]

Anybody know?
Should you be holding the glass tube flat against the white background of the chart when you compare the colour or should you hold it just away from the chart but with the white background of the chart behind it?
Both seem to give very different colours as when you hold it slightly away it is lighter.
Also...it is better to compare the colour in natural light correct?

 

[Bloo]

I do mine by holding it in natural light (not direct sun light) and just a few mm above the chart - so just very slightly away from the chart

 

[Cheffi]

I do it the same as Bloo. You are right tho about how the colour changes depending on which angle you take it from. Saying that there is no doubt about the colour of 0ppm and thats the only one I can read clearly oh and the darkest one. The ones in between ie the pinks are hard.

 

[geo7x]

on the instructions of mine it says to place infront of white card in natural light, so i put it against white card or paper.

 

[Cheffi]

on the instructions of mine it says to place infront of white card in natural light, so i put it against white card or paper.

If you read it again it says to 'view the tube against the 'white area beside the color chart' ie the blank area to the right of the colours, but even so it can still look confusing.

 

[robyngunston]

on the instructions of mine it says to place infront of white card in natural light, so i put it against white card or paper.

If you read it again it says to 'view the tube against the 'white area beside the color chart' ie the blank area to the right of the colours, but even so it can still look confusing.

I agree comparing the colours when the reading is not 0 or very dark can be very confusing

on the instructions of mine it says to place infront of white card in natural light, so i put it against white card or paper.

If you read it again it says to 'view the tube against the 'white area beside the color chart' ie the blank area to the right of the colours, but even so it can still look confusing.

I agree comparing the colours when the reading is not 0 or very dark can be very confusing

Agree about the natural light too.....that makes such a difference in colour as well!

 

[Don155]

I hold it slightly away from the card under natural light. Funny my Nitrite reading never seems to get any darker than 2.0 until it goes a light green color inticating that its offscale high. The Nitrate test as well doesn't seem very accurate as it seems to read at about 5 ppm if there is any NitrIte present at all. If you then leave it sit overnight it'll read 20 - 40 ppm Nitrates in the same water!!

I just use the rule: Any color other than the 0 color indicates positive and positive generally isn't good. (Except for Nitrates which seems it isn't bad unless it reads over 20 - 40 ppm)

 

[Bloo]

(Except for Nitrates which seems it isn't bad unless it reads over 20 - 40 ppm)

Not quite. Many of us sit with tapwater that often have nitrates pushing 50ppm and if rainwater is not an option (living in a flat) and RO not an option (living in a rented flat) you just have to make do with what you have.

My understanding is that anything around the 60ppm mark is still perfectly ok.