Hanna huge discrepancy with new reagent

[ninjamyst]

A few weeks ago, I purchased a Hanna HI774 Phosphate ULR. Last night, I used my last reagent that came with the Hanna. My PO4 has been consistently testing 0.37 for the past week. It was up to 0.50 2.5 weeks ago and I been trying to bring that down with Seachem Phosguard. I last refilled the Phosguard 4 days ago and was about to refill it again since Phosguard exhausts quickly. Today I used a reagent thats part of a new pack. My PO4 tested 0.02. what the heck. I suspected something was wrong because I am getting a bit of dino on the sandbed and my well established Walt Disney acro started to STN.

My hypothesis is that the original reagents that came with my Hanna was a bad batch that tested consistently high? And with me using Seachem Phosguard, I have now drove PO4 way down. My tank likes to run dirty and the sweet spot is 0.10. Or is the new batch of reagent bad? Argh. I am so mad....I thought Hanna was the best and most accurate. I did the test twice tonight. 0.02 and the 0.03.

 

[billyocean]

This will sound dumb but double check and make sure it's the ULR reagent. I've accidentally the LR reagent before and another person I saw post they accidentally grabbed the phosphorus reagent. My ulr reagent is always consistent..every blue moon I get a weird reading and retest and it's fine.

 

[ninjamyst]

This will sound dumb but double check and make sure it's the ULR reagent. I've accidentally the LR reagent before and another person I saw post they accidentally grabbed the phosphorus reagent. My ulr reagent is always consistent..every blue moon I get a weird reading and retest and it's fine.

I did. New reagent says HI774 too

 

[ninjamyst]

I had low nutrients before and dosed NP Plus and my corals were doing great. I thought I dosed too much NP Plus after I got the Hanna so I stopped dosing and started adding Phosguard. A couple of days ago I noticed some corals loosing color and lost a few acro frags. I feel bad putting my tank through nutrient swings and I also made a few posts in other threads bragging about how my tank is doing awesome at 0.50 PO4. Blah.

 

[billyocean]

I had low nutrients before and dosed NP Plus and my corals were doing great. I thought I dosed too much NP Plus after I got the Hanna so I stopped dosing and started adding Phosguard. A couple of days ago I noticed some corals loosing color and lost a few acro frags. I feel bad putting my tank through nutrient swings and I also made a few posts in other threads bragging about how my tank is doing awesome at 0.50 PO4. Blah.

Had to be a bad reagent...that sucks man. Indo known the alk 755s reagent tests .8 lower than the 772s reagent. So if you test alk with hanna makensure your reagent is 772s. SA is the only place that has sent 755s for some reason

 

[92Miata]

I like Hanna's meters - but their reagent supply chain is abysmal. There are constant issues with HI772 reagent, and sporadic issues with pretty much all the others.

 

[shakacuz]

i’m having the same issue but with ALK/no3/po4. i bought new reagent and will test tomorrow but more recently i’ve wanted to switch down to salifert just because i hear of no issues with their kits

 

[billyocean]

I like Hanna's meters - but their reagent supply chain is abysmal. There are constant issues with HI772 reagent, and sporadic issues with pretty much all the others.

The 772 is fine if you keep it in the fridge. The 755 tests .8 lower..both consistent but refrigeration and shake before use is key

 

[92Miata]

The 772 is fine if you keep it in the fridge. The 755 tests .8 lower..both consistent but refrigeration and shake before use is key

Keeping it in the fridge helps, but it is by no means "Fine".

I ran a couple of experiments last year with 772 reagent - and all involved using two bottles at once (one experiment, one control). If the bottles were different batches, they would always give me different numbers when freshly opened. If they were the same batch, it was about 50/50 on whether results would match. (and I'm not talking about being off by .1 - I'm talking different by .5+ dkh)

 

[billyocean]

Keeping it in the fridge helps, but it is by no means "Fine".

I ran a couple of experiments last year with 772 reagent - and all involved using two bottles at once (one experiment, one control). If the bottles were different batches, they would always give me different numbers when freshly opened. If they were the same batch, it was about 50/50 on whether results would match. (and I'm not talking about being off by .1 - I'm talking different by .5+ dkh)

Interesting. Mine reads right what it's supposed to be in range from 8.1-8.3 bottle to bottle