Hanna Alk reagents, replace often!

[Blue Z Reef]

So I was testing my tank a few weeks ago and admittedly hadn't for at least a month, maybe 2. I use my Hanna checker and the test says my Alk is 4.5...holy crap! So I test again, same thing. Test my frag tank, it's like 6.5. I had been swapping water to the frag tank to equalize things with my tank so I fear it has been brining it down.

 

So I do a water change (25 gals) and it only goes up to like 4.7. I tested the Kent mix prior and it said 9. I start thinking this must be a real crash going on.

 

I go to OIAB and buy some ESV 2 part and start dosing that to bring things up. I adjusted my CaRx as well. I'm following the numbers checking each day and it's only going up a few points on the meter...like 98, 101, 103, 110, etc. This goes on for a while as I'm testing daily. I order more reagent as I'm testing so much.

 

Last night I do a water change. Today I go to check it thinking the checker had previously registered 112 (6.272), so it must have gone up after the water change. It reads 98....test again, 98. Then I realize this can't possibly be right! The exp date on the reagent is 11/16, not that old (think I bought it less than 6 months ago). I pop open my new bottle and test, Alk is 9.4! I feel relieved that the tank is not in the "crash zone" still but upset that I can't trust the checker without really fresh reagents!

 

My only theory is they go bad relatively quickly once opened and exp date doesn't really matter. I had tested this before when I found an old unopened reagent that had expired 2 years prior and it read the same as a new one but my opened one was off by a small margin (maybe 10-15%). I didn't expect it to be off by such a large margin though!

 

So long story short, swap your reagents out often ($9 shipped on Amazon prime). I may end up trying the titration method to get a better baseline in the near future :(

Edited January 13, 2016 by Blue Z Reef

[TheClark]

Dang!  Thanks for the share, may save someone out there.

 

I have been keeping a backup alk test but never use it, a salifert.  It comes with calibration fluid so you can test the test kit, pretty cool.  Honestly though I never use it, may do so now...

[Lexinverts]

My problem with the Hannah alk reagent is that after I have had one open for a month or so, it start getting little chunks of things floating in the liquid. When these end up in the tube, they cause my readings to be off. I think I am going to start pouring the reagent through a small plastic mesh to take out the chunky pieces that seem to throw off the reading before I use it.

[LC Scott]

I'm using both now, I was getting back 5s with the titration test.

 

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[Blue Z Reef]

Yeah it's made me start thinking about backups for sure, probably will get a Salifert for now. They also make a calibration reagent for the checker to test it, but I can only find it on Hanna's web site (wouldn't have really helped this situation though).

 

Lex - what was surprising is that the reagent was fine; no chunks and always recapped well and stored in the box when not in use. Also, the fact that the bottle was less than 6 months old really had me wondering. They don't really include anything saying the expiration timeframe after opening so the users just go off the expiration date...which obviously doesn't seem to matter.

[zechirian]

Ran in to something very similar.  I was doing PO4, CA and ALK with Hanna and noticed tips starting to burn but my ALK and CA were 8.2 and 400 with Hanna.  Grabbed some salifert tests and got a 12.5 and 460.  I don't do the hanna checkers anymore except for the PO4.

[Mandinga]

As much as I like my Hanna for coolness...I get 100 tests out of my ol salifert, and I guarantee I can do the salifert test faster than the Hanna checker. READY SET GO.