AP test kit question

[jcarlilesiu]

So, I have been testing my water for some time now, and i have a question regarding reading the test results. Maybe im just stupid, as this seems like a stupid question, but im going to break down and ask.

It says in the booklet to compare the test vial in the white area next to the card which has the color coded bars. Hey no big deal right? HOWEVER, if i hold the tube flush with the card it appears darker than if i hold it a 1/8 or a 1/4 of an inch away and in front of the white. This can vary the test results pretty dramatically. Today I tested my nitrates, and holding the tube flush with the white background provided for a darker "20 ppm" reading, holding it a tiny bit away showed a solid "10 ppm".... am I stupid? 8O

 

[jsoong]

Read this:

http://www.aquariumadvice.com/viewtopic.php?t=76334

Lots of people also have trouble deciphering the color.

 

[jcarlilesiu]

i guess this is along the same lines, im just curious the methods that others use when reading it... not so much that i can't decipher colors, more that the colors vary at what location you read them.

 

[severum mama]

I always take the card and test tube outside in natural light, and hold the tube right against the card. I hope I'm right, as I haven't given this much thought before!

 

[rich311k]

I hold mine against the card, that is what the instructions say. I try to read it in the sunlight.

 

[Zagz]

I hold mine against the card as well and in as bright a natural light as possible.

 

[tropicfishman]

obviously its going to be darker holding agianst anything, on nitrates, i go by this simple rule, if its red, time to do a water change

 

[Fishyfanatic]

I don't even hold it against the cards. I line the tubes up on the kitchen counter and wait 5 minutes. I can tell just by glancing at them if there is a problem. I don't like the Nitrate vial to be red so if I look at it and it appears red, I do another water change.

 

[brant]

Pretty much if it goes above the the orange or even at the orange its time for a pwc I do weekly 30% to 50% changes and have not yet reached the red. Also you can cut down on alot of the nitrates by simply cleening filter material more often I rinse out mine mabye twice a week and they are always very dirty but that is mostly from the plecos chewing up the wood. Oh and if you grow plants Indoor or outdoor rinse your filter into a bucket and put some of that on your plants woo hoo baby it out perform any commercialy marketed fertilizer I have used including miriacle grow.

 

[jcarlilesiu]

i always keep my nitrates at around 20 ppm (red) because that is what im supposed to do from my understanding of keeping a heavily planted tank. Maybe im misinformed here.

 

[Slarty Bartfast]

Block out the colors

I've found that when trying to decide between one color or the band next to it, it helps if I block out those colors with my finger one at a time until one makes sense. If both are exposed, and you're "between" them, then it's easy to just sit there and stare....

I, too, hold it right against the card, and find a nice light to light things up.

 

[Mazdaman]

i set the card on my white window sill and let the tube stand on the white section and I get pretty good readings. I think the key is maintaining levels as the test aren't %100 accurate and more to make sure levels are staying pretty constant.