OK so here is my question? I am testing the pH in my reef if I look at the tube held sideways next to the color card by my fish tank that is very bright My pH best matches the color 8.0. If I look down throw the test tube the color is darker and reads right at the recommend 8.2, also if I look at the test tube sideways just a couple of feet from the tank where it is not getting blasted with tank light it reads 8.2. How are you supposed to and in what light are you supposed to read these cards??? do you look down thorough the tube or the side of it? for years I have been looking at the side of it but then i read some where if you are having a hard time determine the color next to the card look down throw the bottom but this changes the color by one shade.  I don't want to be adjusting something that duse not need adjusting? But I am trying to keep more demanding corals now and want to get this right so they don't dye on me. thanks Glen
What brand of test kit are you using? I've always been under the impression that color comparisons test are best made in a well-lit area. PH can also swing... depending on the time of day the test is done. I'm not sure I would worry about an 8.0 to 8.2 change... but but that is just my opinion.
There should be a picture of the matching position on the card that tells you how to view the tube. it should say "view from top or view from side". Go outside if you can. The light from the tank, color of your walls and wavelength of your overhead lights can all change the color of your sample. Natural light is best.
WOW so simple but you are right with all the blue light our tanks throw off it would look different. Thanks for your help. API REEF Master Kit and Saltwater Master Liquid test kits. HAHA OK I am not usually this dumb but I just looked at the back of the cards for both test and they show exactly how many drops to put in how long to test and how to hold the test tube. I have been getting the book out every time I test to see how many drops to put in and never even looked at the back of the cards. lol nobody's perfect! Thanks this will be much easer, Glen
