Api Ph Test Confusion

[cchris]

my test with low ph liquid is always darker than 7.6
but
my tests with the high ph liquid has recently been lower than 7.4
 
I dont get it.
 
high ph from tap is very high.. seems to go down after being in the tank a while.

 

[Ilyas]

Do you use drift wood? Drift wood stabalizes PH to around 7.4.

 

[Donya]

This isn't all that uncommon a situation with those two test kits. On the normal kit, you are nearing the high end of the range and on the other you are near the low end - and the colors aren't the best to tell apart usually in those ranges. There is also always some small margin of error on the kits and color cards. If the results are differing by more than 0.2 consistently, particularly if it wasn't the case in the past, then it would be worth taking sample to a store and ask them to check with another kit to see whether one of your reagent bottles needs replacing. Also, if you've had these kits for a while, make sure the test tubes are completely clean. If you are using tap to clean the tubes and have hard water, try giving them a clean with some vinegar (soak for a bit with vinegar then washing out with distilled water is best). Small carbonate desposits can get into the tubes after many cleanings with hard tap water and throw results off.

 

[cchris]

no driftwood yet, have some on order but havent recieved it yet.
thanks for the information, ill clean the tubes tonight.

 

[Scates11]

Do you use drift wood? Drift wood stabalizes PH to around 7.4.

 
No offense but I have to disagree with this....I use wood in my tank and my pH is 8.0, wood can lower pH but it's not a sure thing that it goes to 7.4 at all. 

 

[Lunar Jetman]

I think all you've shown is the inaccuracy of test kits...

 

[The Taffy Apple]

I would say that if a difference of upto 0.2 is the main issue here, then don't worry so much about it.
What would concern me is the way your tap water PH drops after time in your tank.
Maybe you should carry out a KH/GH water hardness test (£4/5, eBay) on your tap water...this will tell you the hardness or softness of the water your supply gives to you...IE; I live in a very soft water area...it is 7.4/7.6 out of the tap yet can, and will, drop to below 6.0 over time...i combat that by adding a small amount of crushed coral into my filter, which in turn keeps my buffering capacity high and a regular PH of 7.0/7.2.
 
Terry.