Reducing PO4 With Phosphat-E, When to Stop

[cjpitt80]

Hello. I've been using Brightwell Aquatics Phosphat-E to reduce phosphate levels. I do not have room for a reactor and GFO was ineffective, as I was only able to keep it in a bag and run it passively. I run a Triton system with limited mechanical filtration (no filter socks, just a nylon stocking type filter over the return intake to keep broken pieces of chaeto out of the display). When I started, I had .11ppm PO4 as tested by the Hanna Ultra Low Range (ULR) checker. I have a 75gal tank with 29 sump. I estimate 80gal water after displacement by live rock, sand, and equipment. The directions indicate 1mL will remove 1ppm in 4 gal water, or 20mL will remove 1ppm in 80gal. Therefore, 1mL will remove .05ppm in 80gal. I dosed my tank 1mL with an expectation of a .06ppm reading, subsequently. When I checked the PO4 again the next day, it read .19ppm I dosed another 1mL that day and the following day (day 3) the PO4 reading was .16ppm. The directions state "Phosphate test kits may show a false-positive reading after aquarium has been treated; this is a result of the chemical mechanism by which phosphate test kits operate and does not indicate that the product has failed to perform its intended function." I take this to mean you will get a higher reading than what the actual REACTIVE phosphate is.


My question is IF this is happening, how do I know what the ACTUAL level is and WHEN to stop using the product? How do I remove the bound phosphate, get an accurate reading of organic, reactive phosphate and know when to stop? Because of my setup, I have very limited mechanical filtration, and I don't have filter socks. Should I skim "wetter" and have a light tea color skimmate, or shoot for a coffee colored dark skimmate? Should I discard some of the chaeto? Should I just do the math and "assume" it works and never know the actual reactive phosphate concentration? I'm running Triton Method and don't do water changes much (only when cleaning gunk from sump). I don't want to keep adding phosphat-E and drive the reactive phosphate TOO low too fast for coral health.
Thanks.

Some Details:


Approx 80gal total system water
Type of filtration
Sump with skimmer. Live rock, live sand, chaeto in refugium lit opposite main tank lights
Type of lighting
Current Marine Pro LED supplemented by Dual T5 NO
Brand of salt being used
Read Sea Blue Bucket
Type of fish being kept
Clowns, Flasher Wrasse, Watchman Goby, Algae Blenny, Bristle Tooth Tang, Chromis
Type of invertebrates being kept
Coral Banded Shrimp, Fire Shrimp, Cleaner Shrimp Various Clean up crew snails, hermits
Type of supplements being used
Daily Triton Dosing. Daily KZ LPS Amino Acids
Type of fish food being used
Mostly Frozen. Reef Frenzy, Occasional Pellets
Type of invertebrate food being used
Reef Frenzy. Reef Roids
Medications used in the last 3 months
Flucanozole
Water Parameters
pH
7.9 night 8.2 day
Alkalinity
8.1-8.3
Salinity
1.025
Ammonia
0
Nitrite
0
Nitrate
apprx 3ppm
Water change frequency
Triton Method Apprx 5% every other week to clean sump. RODI water used to mix salt

 

[Vinny Kreyling]

When is your next Triton water test?
Corals can survive higher phosphate readings it's just that we want it low for algae.
I would take it to .08 ppm & have the water test.

 

[Peter Eichler]

I assume this stuff is just super overpriced lanthanum chloride? It's not like Brightwell has ever done anything innovative, so it's probably a safe guess. If I'm correct you really should be dripping a diluted form of it and using a filter sock or some type of particulate filter and dosing in a slow drip just prior to the sock. Or even better, don't worry so much about your phosphate levels.

 

[cjpitt80]

When is your next Triton water test?
Corals can survive higher phosphate readings it's just that we want it low for algae.
I would take it to .08 ppm & have the water test.

I'm along your lines in terms of thinking, but again HOW do I go about doing that I'd I don't have an accurate way of measuring? Does Triton measure phosphate any differently than the Hanna test? I can send off a Triton sample whenever.

 

[cjpitt80]

I assume this stuff is just super overpriced lanthanum chloride? It's not like Brightwell has ever done anything innovative, so it's probably a safe guess. If I'm correct you really should be dripping a diluted form of it and using a filter sock or some type of particulate filter and dosing in a slow drip just prior to the sock. Or even better, don't worry so much about your phosphate levels.

Don't know what the stuff is other than ultrapure water and "proprietary phosphate reducing blend." I used per directions on bottle, no mention of diluting or dripping. I guess I could try tying a filter sock to the intake.
I'm starting with some SPS "The thing Acro" Bubblegum Digi, various Montiporas, don't I want phosphates "near-zero" and not above 0.05ppm for any significant amount of time?

 

[Vinny Kreyling]

Since you can send a sample anytime check your water, mark the results down & send a sample the same day.
You will then have 2 results on the same sample, one with your kit, one with theirs.
Then you can see the difference.

 

[cjpitt80]

Since you can send a sample anytime check your water, mark the results down & send a sample the same day.
You will then have 2 results on the same sample, one with your kit, one with theirs.
Then you can see the difference.

I've actually done that before (prior to dosing) and there is a difference. Issue is, I don't know which is "right". I dosed again and the Hanna meter showed 0.22ppm, up from 0.16ppm. So I'm unsure if I'm reading reactive vs bound phosphates with the Hanna and what Triton detects and therefore, not sure when to stop dosing. So yeah....?? Not sure what to do now. There's no algae in the display so I may just let it ride out and see how the SPS does I guess

 

[Vinny Kreyling]

I would trust the ICP more than the Hanna.
There are other places to get the water tested also, for comparison.

 

[cjpitt80]

Yep, just heard back from Tim at Triton. He says ICP tests for Phosphorus, both organic and inorganic
So it's very likely this will also return a false increased level