Phosphate test kit

I use an API phosphate test kit and I'm pretty sure it's useless. My reading has been .25 for a few weeks. I decided to test my R/O water, some distilled water, tap water and drinking water. Somehow they all read .25
Anyone else have an issue with this test kit? I realize I need a new one that reads between 0 and .25 anyway but this thing is worthless.

 

Like you said they're useless. You need a low range kit.. might as well get the Hanna checker.
Hanna Checker Phosphate PO4 Colorimeter - Bulk Reef Supply

 

+1

API is ok for getting you through the nitrogen cycle and accustomed to testing, but not much else.

 

don't be worried, the API test kit when it reads slightly colored, it's usually close to 0 your actual water. In my opinion, if my API test kit tests that low, my tank is doing just fine and not worried about it. I have a bunch of SPS that are growing great with that reading.

 

Problem is, every tank is different. With an actual PO4 level of .25, corals suffer and nuisance algae takes over. Optimum reading is .03. One can't possibly maintain it properly without an accurate reading.

 

Don't get the phosphate get the phosphorus ULR colorimeter.

 

.25 is pretty high. My point was that with the API test kits, I've never seen it at that first color shade. it has always read between 0 and .25 due to the fact that their kits aren't really the most precise ones. good for ball park figure.

 

.25 is not just hight it's off the scale for an SPS tank. . API kit is a high range kit. It will always read zero unless you have a real PO4 problem. If it reads anything other than zero you got some issues. The only way to tell what your PO4 is is to get a low range kit.

 

good point...gotta pay the bigger bucks for precision.