Neptune Aquatics

Got the 'Zero PO4 Blues'

Squist

Squist

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My tank is recently launched--4 months since starting the cycle. Parameters are good but phosphate is undetectable. Curious what you might recommend I do to add phosphate. Thinking of using Seachem Flourish Phosphorus.

Parameters:
NO3: 2 ppm
PO4: 0
pH: 8.15
Alk: 8.5
Ca: 500
Mg: 1500

The tank is 255 L (RSR). Counting the capacity of the refugium (converted the ATO to fuge), the tank's about 70 gal. I've been doing an auto 2.5 L water change daily. Beginning today, I've cut back to 1.5 L (500 ml 3x a day).

Filtration: filter socks, protein skimmer, and marinepure bio cubes; minimalist rock in display.

I target feed frozen food to 8 fish. Reefroid target feeding 1-2 times a week to a dozen frags that seem to be doing fairly well, except for a stylophora frag that appears to be bleaching. I added that mid-July.

Tips you care to share? TIA.
 
I had the same problem when I set up this tank. I ended up dosing Brightwell neophos and neonitro for a few months until feeding and buildup in the sump finally started picking up the slack.

The one caveat I would warn about is to make sure your test kits aren’t giving you a false negative. I went through three different nitrate test kits and finally realized none of them were working when I tested the bottle of neonitro straight and got nothing. Salifert was the only test kit that seemed to accurately report nitrate for me. I don’t think I would dose phosphate until I confirmed with a Hanna ultra low phosphate checker to confirm zero.
 
My new tank I had 0 nitrate and 0 phosphate. I use the salifert nitrate which I like. For phosphate I truly believe you need the Hanna ulr. If your running 0 and you wanna bring it up to .02 no other test kit can read by the .01. I dose seachem flourish phosphorus and the seachem flourish nitrogen. They both work. I barely use any phosphorus as you barley need any. The nitrogen I use quite a bit. I got my nitrates up to steady 5 and phosphate to .03
 
Feed feed feed. But start dosing phyto and aminos with some reef roids or other type food in the mix and I guarantee before long you’ll have to dial it back but the corals will love it.
 
The_Lazy_Reefer said:
Feed feed feed. But start dosing phyto and aminos with some reef roids or other type food in the mix and I guarantee before long you’ll have to dial it back but the corals will love it.
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Would you pull the filter socks for a while while increasing feeding at this stage? How about the skimmer? Maybe cut that back? I've got Apex--I could schedule it for partial day.

I was afraid that I was creating a mess of algae from what I was feeding and I cut back. I was unsure if the "uglies" the tank was experiencing was accelerated by it.

Since August 1, I've been dosing 15-20 ml of phytoplankton every (other) day. OceanMagik from AlgaeBarn. And I've been maybe too conservative with the reefroids. Again, concerned about too much algae; I've had a bloom of bubble that a newly added emerald crab is feasting.
 
A Aaron said:
My new tank I had 0 nitrate and 0 phosphate. I use the salifert nitrate which I like. For phosphate I truly believe you need the Hanna ulr. ... I dose seachem flourish phosphorus and the seachem flourish nitrogen.
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Thanks! I just got a Salifert PO4 kit today. Apparently it can measure 0.03 by what its visual comparison card suggests. I'll look into the Hanna ULR. Thanks for the tip!
 
1) As stated, measuring low phosphate is tricky. I have the Red Sea Pro and Hanna ULR kits and prefer the Hanna for repeatability, although obviously there is a cost an nuisance to use factor. I can't speak to the Salifert kit, but if it reads there you should be ok.
2) If you have algae growth and no dinos it isn't a hard zero.
3) Feeding more works, as does dosing directly. Last time I dosed I used KH2PO4 because I had it on hand. It doesn't take much. My last tank ran a phosphate surplus and a nitrate shortage, so I didn't need to use any there.
4) Keep the CUC going.
5) If you really do have low nitrate (2 PPM is ok, but don't let it hit zero) and no phosphate the filter socks aren't doing a ton other than (maybe) making your water clearer.
 
I removed my filter floss thinking it would accelerate the nitrates and phosphate by letting it decompose in the tank but the water and tank itself just looked worse the next day. I’ve tried 3 times but always put it right back in. Dose acro power or another amino that boosts it big time. Nothing raises your numbers faster then reef roids or reef chili. The regular food made no difference but dump in reef roids everyday for a week and you’ll get some type of reading. I also run the skimmer 12 hours a day, run my refugium light 2 hours a day just to keep the thing going and I keep only a soft ball size of chaeto. I made it as ineffective as possible without shutting it down because I will eventually need jt
 
A Aaron said:
... Nothing raises your numbers faster then reef roids ... dump in reef roids everyday for a week and you’ll get some type of reading.
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Got it! I’ve got a jar of roids. Going to get on a similar program starting tomorrow.

When you say: “dump in every day for a week” what quantity are you talking about? Do you have a ratio of roids:gal you keep in mind? I’ve got a 70 gal system.

A Aaron said:
I also run the skimmer 12 hours a day, run my refugium light 2 hours a day
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Nice. Will program the timing. Suspecting that there isn’t a time of day that matters. I’ll just go on-off for a few hours at a time throughout a 24-hr cycle.
 
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I’m sure there are theories about when it would be better to run the skimmer the 12 hours but I don’t think it matters. For the reef roids it really can raise your nutrients so I would start small and do 1/4 teaspoon up to 1/2 teaspoon everyday. I’d test every couple days so you don’t over do it. For our tank you may need to do it twice a day for a while. You just need to start and test and see what happens. Once your tank starts making and holding the nutrients you’ll need to cut back to your regular 2 times a week or whatever so that’s why you need to be testing regularly. Another thing I do for now is use a auto feeder to feed during the day when I’m at work. I feed pellets with reef roids mixed in just to make sure food is going in consistently. Just another option.
 
UPDATE: feeding 1/4 tsp ReefRoids daily for a week (~65 gal tank) along with daily “tab” of frozen brine and 20 ml OceanMagik phytoplankton. Nitrate doubled from 2 to 4 ppm. PO4 still undetectable.

Skimmer running 1/2-time, alternating on/off on hourly basis. Auto-water changes ceased.

Holding steady and feeding, feeding, feeding.

Others parameters: no change. dKH 8, mg 1600, Ca: 440, pH: 8.1 (as of today)
 
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