Salivary v Hanna for Phosphate

[Clarinuto]

So I’ve been using Salifert to test Phosphate, but picked up the low range Hanna on sale this past weekend thinking it would be easier and more accurate. I tested for the first time today using both. Salifert says .03 and Hanna says .31. That is not even close to the same result. I now feel like my phosphate is way higher than I thought or that one of the tests are inaccurate or were screwed up by me. What say ye?

I really don’t feel like I could have messed up either test. Salifert I’m super used to at this point. Hanna I did the whole 10 ml untreated then add the packet and shake for 2 minutes, wait for 3 minutes, and then test.

I’ll be honest, I really want to believe Salifert (of course) and also the Salifert test is much easier to do though the accuracy of reading it is probably lower.

I don’t have a third test kit to break the tie

 

[Clarinuto]

I forgot to mention that I did have the issue of the checker timing out before I could get C2 in the thing. I just decided to fill vial 2 with untreated water and redo the test. I didn’t think this time would change the results but I guess technically C2 did likely sit a little longer than 3 minutes.

 

[Waters]

Chances are if you did have a third test, you would get a third different answer. I am never 100% confident with any test kit (although I do use Hanna for Phosphates). I use them more to see trends....as long as the Salifert is consistent and you tank looks good, I would go with whichever you feel the most comfortable with.

 

[Clarinuto]

Chances are if you did have a third test, you would get a third different answer. I am never 100% confident with any test kit (although I do use Hanna for Phosphates). I use them more to see trends....as long as the Salifert is consistent and you tank looks good, I would go with whichever you feel the most comfortable with.

Thank you! I really appreciate this answer. I was expecting people to say that I needed to defer to Hanna as it was likely more accurate, but I think you are right... consistency is likely more important than a specific number within reason

 

[Redleg]

Did you use the conversion table with the hanna checker?

 

[Jason mack]

I would always go with the Hanna checker .. but as mentioned above , did you convert it , the ulr you need too x by 3.066 then devide by 1000 .. so if the Hanna read 31 it’s 31 x3.066 then devide by 1000 so it would be 0.09 ..
When doing saliferts test .... when filling the syringe with 1 ml reagent ... push the plunger down too the 1 ml mark .. there will be an air bubble ... this should read 8.5 .. try and do this with all saliferts tests .. sometimes it takes a few try’s of filling and emptying to achieve this .. but then you will be starting from the same point everytime ..
And as last .. as also mentioned above these are hobby grade tests .. and I use mine more as a guide .. your corals will tell you more ... if your tank looks good .. don’t chase numbers ...
but I would go with the Hanna over saliferts for phos !!

 

[Jason mack]

I forgot to mention that I did have the issue of the checker timing out before I could get C2 in the thing. I just decided to fill vial 2 with untreated water and redo the test. I didn’t think this time would change the results but I guess technically C2 did likely sit a little longer than 3 minutes.

I use two vials as well !!!

 

[lion king]

The hanna checker is much more accurate, but you have to be perfect with your testing procedures. I picked these up to help with adding the reagents. https://www.amazon.com/gp/product/B009CZEQ36/ref=oh_aui_search_detailpage?ie=UTF8&psc=1
While I have found every other phosphate test kit reading really lower than probable, that is a big difference while using the regular hanna phosphate checker. I would do the test again and really really be as precise as you can with your methods.

I was having a cyano issue while the red sea and salifert both showed my phosphate near 0, the hanna detected a much higher phosphate level; when I corrected the phosphate my cyano disappeared. I do the hanna ulr tester, which does give a more precise reading at lower levels. the problem is most test kits can't read at lower levels.

 

[Clarinuto]

Apologies for leaving this thread dangling. I am having a different tank issue that I wanted to sort first and will work on figuring out what I did wrong with Hanna after