Is Instant Ocean the source of my Phosphate issue?

[TylerHaworth]

Tank inception was March 2013. 150 Gallon 36x36.

Prior to about 8 weeks ago my tank was cruising along very well, Acros growing reasonably and coloring up superbly.

Parameters rock solid at 1350Mag 420Cal and 7.8-8.0 DKH with Nitrates 0.2 to 0.5 with Salifert and Phosphates between 0.03 and 0.05.

When all of a sudden, EVERYTHING (~25 SPS pieces) RTN'ed over about a 5 day period… I still don't have the slightest of clues as to what happened or why, but that's not why Im here…

I had a massive nutrient spike and algae bloom after the mass death that took me up to about 5ppm Nitrates and .15 Phosphates…

Ive since handled the Nitrates well and they're back into my preferred range of <1.0, however the Phosphates just absolutely will not drop down below .07 even while changing 2 cups of GFO every single week with my regular back to back 10 gallon water changes.

Today in frustration I decided to test my freshly made water. I wipe out my mixing barrel (The same Rubbermaid Brute that I've been using for 5 years) every time I make and use a batch of water. I run a 6 stage RO/DI setup(sediment, carbon, carbon, RO, DI, DI) where the water coming out of the RO membrane registers 1ppm TDS and after the first DI resin registers 0ppm TDS… After mixing to 1.026 and letting settle for 12 hours I took a reading of .043 Phosphates in brand new water.

Ive never been compelled to test my freshly made water for nutrients… Is this normal for a batch of freshly made IO? Did I get a bad batch? What gives?

Additional Information:

Feed one cube of mysis daily in two feedings, with an patch of Nori about twice per week.
One Foxface, Two Anthias, Two Occ. Clowns, Goby, Bellus Angel, Yellow Assessor.
Rocks are blown off before water change each week and rarely produce much detritus.
Sump is vacuumed each week during water change
SRO XP2000 Skimmer
GFO and Carbon Reactors
Vinegar Dosed
No visible algae in display

 

[bertoni]

Does some freshly-made RO/DI measure zero? There might be some problems with the phosphate kit, but the salt product might be contaminated, too.

 

[TylerHaworth]

To be honest I haven't tested pure RO/DI, I figured my Hanna ULR may not read properly with pure water instead of salt... I have used hanna reagent packs from two separate batches with very close results (Within 2ppb.)

I will check that tomorrow... What is my plan of action if the RO/DI water is reading high Phosphates?

 

[Timfish]

I'm pretty confident it's not IO salt. I've used Elos Professional to test my water and found no difference before or after adding it. You say your corals were coloring up real well, were they losing their brown coloration?

 

[TylerHaworth]

They were well colored and growing well prior to the crash, I have no SPS left now except for one small Monti Setosa... That's really irrelevant atm though since they've all been gone for nearly two months.

I've used IO exclusively for years and never had Phosphate issues like this. Hopefully after I run a phos test on pure RO DI I can jut chalk this up to a bad batch of salt and move on.

 

[bertoni]

You might be correct about the Hanna meter not working with RO/DI. The Phosphorus ULR is rated only for saltwater. I'm not sure which model you have.

I'd get a second opinion before doing anything drastic or spending a lot of money.

 

[Big E]

One easy way to check is to run about 5 gallons of fresh water through GFO for aboout an hour and then mix with the IO salt. Check the phosphate levels after it's completely mixed the next day.

It's usually your RO system that's the failure and it's likely your membrane needs replacing.

 

[TylerHaworth]

It is the ULR Phosphorous meter Bertoni…

Ed, that is a great idea, I will try and set this all in motion… with a nicely controlled experiment.

Thanks for the insight folks, very much!

 

[TylerHaworth]

For the sake of following up:

-Made 5 gallons fresh RO/DI water
-Ran fresh ro/di through a brand new canister with two cups of BRS GFO for 8 hours
-Mixed salt overnight
-Took readings of 12-20ppb Phos on my Hanna ULR =(

Out with that batch of salt, hopefully the next box tests a little better...

 

[bertoni]

That's discouraging. Good luck with the next batch.

 

[AugustWest]

You're putting a lot of faith in that Hanna ULR checker. I wouldn't be dumping salt water based on the reading you're getting alone.

 

[TylerHaworth]

The Phosphate level goes up when I do a water change, it goes down when I add new GFO, confirmed via three different batches of reagent… The pattern fits, and doesn't seem to point toward a bad test unit.

I only just put two and two together that the mass die off happened right after I got into the bags of salt from that one particular box… Prior to that I had the overall best growth and color I've ever had… Everything points toward a destructive catalyst of some sort… Hopefully I'm right here.

It's only one 50G bag of salt I tossed anyway, not a significant loss even if I am completely dead wrong.

 

[TylerHaworth]

Just a follow up to my follow up... New box of IO plus a couple water changes and my P04 is back down into the green zone at 0.04.

 

[nicholasb]

A t.d.s meter will not show up phosphates, but 0 t.d.s should mean 0 phosphates. Saliferts test will work in fresh water. Sorry to hear about your S.P.S. I losst a big bit of green plate monti, and pink birds nest both 2 years, old just like that. Life sucks some times.

 

[bertoni]

A very precise TDS meter will detect phosphate in water, but it'd have to be more precise than most of the instruments I've seen in use unless the phosphate level was very high by our standards. 0.03 ppm of phosphate is going to measure very low on a TDS meter, for example.

 

[dkeller_nc]

Just a note, but I'm thinking most would be of the opinion that even a fairly large dose of phosphate wouldn't wipe out a tank full of corals by RTN. There are lots of other potential causes, though.

 

[OffDaHook]

Maybe its the brute trash can leeching phosphates.

 

[TylerHaworth]

The TL : DR here - Started using a new box of IO and bad stuff started happening, ceased using said box of IO and good stuff has started happening since moving to a different box.

Wasn't the Brute, I made and tested water in buckets that tested high as well.

I think it was just a bad box of salt with high phosphates being only one of multiple problems.

 

[pscott99]

You should consider sending a sample to the supplier with your story. That is very sad for other users who may not realize it or test to the extent that you did. One small bag of salt is not a batch I suspect.

 

[bertoni]

Oh, sigh, I'm glad you've found the source of the problem, at least.