Phosphate Conundrum.

So after weeks of fighting phosphates of .11 a .20 on Hanna, I went out and bought a Salifert test kit. The kit is new, the date is current, and it shows 0.00 phosphates. Which do I believe?

I have very little algae, but my corals still look quite dark. I'm confused.

 

Retest with both again TWICE find out which is consistent,

 

They're both fairly consistent. I've done loads of tests with Hanna including 3 today and I just ran the Salifert 3 times.

 

If you have some algae then it's probably not zero. Take a sample to a store and have them check.

 

My Salifert PO4 test has never read anything other than zero.I don't believe it...total waste of money.

 

+1, if there is any algae you will be getting a false reading.

 

Agreed.

IIRC, Salifert only tests for organic PO4. If you have algae, organic PO4 will read zero as the algae consumes it much the same way the bio-filter consumes Ammonia. Hanna, OTOH, checks organic and non-organic Phosphate, which gives a better idea of how much total Phosphate is being introduced into your tank.

Personally, I prefer to keep a little algae growth in the tank; it helps regulate PO4 (and NO3), and provides food for herbivores, omnivores, and CuC. When you start chasing numbers and stressing over algae, the hobby can quickly become a daunting chore. One should relax and let nature take it's course. But that's just my opinion.

 

For what it's worth, I have no algae if any note in my tank.

 

+++1 Well stated. Great advice.

I actually let the algea in my sump grow so the CuC does not get overwhelmed in the tank. Never had a problem in DT and don't measure PO4. Works for me, knock in wood.

 

Do they have something other than API, Hanna, Salifert, etc?

What's that going to prove? I'm not saying I'm right here, I'd just like to know about their magical/more accurate test kit than a Hanna or Salifert.

And FWIW, my API always reads 0 for my phos too, but I'll bet there's some.
But, when my plethera of coral look good, and I can keep the cyano off the CC bed, I'm good to go. I RARELY even test for it.
But I do understand the OP has concerns about his coral health. Could it be light? Probably not, just asking.