Advice? Hanna Phosphate checker

My Hanna Checker Phosphate test kit is giving me readings of 0. Its always worked fine for me. I tested 3 times today - once from each of my 3 tanks. Now I could believe a 0 reading for one of my tanks, but not all 3.

Anyone have any idea as to what the problem might be? Or what else to do to confirm the remote (almost 0%) chance that the 0 reading is accurate.

 

The expiration date on my reagants is 05/2018. So that's not it.

 

I've had bad reagents before (not expired) they just gave me crazy readings. I was getting super high readings though rather than 0. I hadn't figured out it was the reagents until I was almost all the way through the pack of 25... I was doing all sorts of things trying to get PO4 down in the meantime.

 

I know Hannah has some standards you can buy that will give you a 0 and a known reading above 0 so you can verify accuracy of your meter, and when you're done you have 2 spare test vials.

 

I'd be curious to see what you find out, I get the same thing but I only have my DT and I can hardly get macro to grow in my fuge with a AI Hydra 26 on it. Always wondered if it were true or if there was some kind of a common issue.

 

keep in mind that it has a resolution of -/+ .04

http://hannainst.com/downloads/dl/file/id/1053/ist713_03_13.pdf

 

Mines almost always 0 as well. After I clean my scrubber screen it shows some or a day or two after I trim algae off my rock it does as well. Most of your phosphate is probably bound in algae or rock or other organisms that feed on it. And there's probably some, but as said the resolution can explain that variance +/- .04

 

Bud - I'll stop over and get a sample of your water. I'll call before I come. Maybe I can make it late this afternoon after you get home from work.

 

Got a water sample from Bud yesterday evening. Tested it today. Also changed the battery on my checker. Got a definite reading on phosphate from Bud's water sample. Retested the frag tank and got a reading of .03 ppm retested the DT and got 0 again. I've been dosing vodka/vinegar in the DT and cube tanks but not the frag tank so maybe the 0 reading is correct with the margin of error.

 

When I get a 0 reading on my Hanna, I can usually see that it's probably right because my glass won't need cleaned for over a week and sps colors are a bit pale.

 

When i test mine with the hanna checker i always get 0 because my hair algae is eating it all hahah

 

Changing the battery was good. Just feed your DT a little more and you'll get some PO4 back or dose some Seachem's Phos if you have it