API Phosphate test kit?

[Radioheadx14]

I bought an API test kit for phosphate and it sucks! first the reading card has a color code that measures 0, 0.25ppm, 0.50ppm, 1ppm etc. second, i did the test and my color came out pale tan while the color code is from light green to dark blue... ***?

Should i try to take this back and get something else? Anyone have experience with these kits?

I have an API calcium kit and nitrogen kits and they are nice, and a salfifert dKH kit which rocks too...

suggestions?

 

[HBtank]

None of the phosphate test kits that are relatively cheap are all that usefull IME. The Salifert may be the best bet for under $50, but it gets varied reviews.

 

[Radioheadx14]

should i even bother then? I mean, if i dont have a huge algae problem at the moment?

 

[dwd5813]

the pale tan is zero if i remember correctly. hang on, i'll see if i can find my card.
edit: yep, on the card i have, pale tan/yellowish color = 0

 

[Hop]

Po4 kits are pretty weak for our purposes any way, as the majority of Po4 is being taken up by things like algae, so it's really only a reference.

 

[Nanz]

Pale Tan is 0. I thought the same thing when I tested my water. Try getting a sample of tap water and test it or even soapy water. It will turn green/blue.

When I doubt the testing I always find a reference to compare the results with.

The test is cheap but it works. Who cares what the value is in PO4 as long as its undetectible.

 

[HBtank]

^^^
Undetectable with a cheap test kit is not always enough.

The value does matter when you are aiming for less than .03, you need one that can see a .3 vs .03

Low values will measure as 0 on almost every test kit except the expensive ones.

Generally only SPS filled tanks would need this, as the cost is not all that much considering someone may have 1000's of dollars in corals that demand low phosphate.

 

[Mavrk]

I think the best use for less expensive phosphate tests is to tell you when to change your phosban. Always assume you have phosphates in the rocks, etc. If you can detect it, then it is too high.