Phosphate is all over the place.

[ReefHunter006]

Background:
Net water volume: 60gals
Mixed reef
Ammonia: 0
Nitrite: 0
Nitrate: 4-8ppm (color is difficult to distinguish
Ph: night 7.6 / day 7.8
Alk: 8.9
Cal: 530
Mag: 1395
Temp: 78.9 ish
Phosphate: 24 hour range .03 - .113

Dosing: Daily unless specified otherwise

Esv b ionic 2 part 9ml
NOPOX 5 ml
Algae barn phyto 30ml (recently switched from growing my own)
Red Sea coral nutrition a+b 4ml each

Feeding:

Various frozen foods: 2 cubes a day. Recently upped from 1 cube a day that would be cut in half and fed in the morning and evening.

Reef roids: 1/4 teaspoon daily. (Started this regimen two days ago as phosphates we’re testing at 0.

Nori: 1/4 sheet daily

Additional Info:

My ph recently dropped to a low of 7.6 in the middle of the day. Possible that the smoke from the wildfires impacted this since doors and windows needed to be closed all day.

All SPS appear to be failing in this tank.I have been unable to determine a cause. Either Nitrates are to high, ph has been to low consistently, or I am missing something else. I test alk daily, cal weekly, and mag every two weeks. I usually test ph once a month.

A small cyano outbreak has shown up in the last two months. It’s a lighter red color and isn’t everywhere (yet).

Problem:

In an attempt to figure out my SPS issue I started looking everywhere for what would be causing an problems. My first red flag was PH at 7.6 around noon. I got concerned it would drop lower the evening. My Hanna ph checker did not read a drop at 11pm that night, and when air quality improved the PH moved up a couple ticks a few days later to 7.8. I moved 200ml of water outside and the PH moved up to 7.9. 200ml of water in the house and the tank stayed at 7.8. SPS has been having a rough time in my tank before this and I am not sure how low PH has dropped in the months prior. I have had three cases of RTN and my monti frag has been in the tank for 3 months and been paling and experiencing STN.

1.This issue has to do with phosphates. I noticed phosphates has zeroed out on 9/08/20 @ 19:43 and 9/12/20 @ 11:17. I didn’t think much of it at the time because I figured since I have cyano that phos is in the tank somewhere.

I was looking in the tank the next night and noticed how clean the sand looked. I thought what if the cyano releases extra phosphates into the water at night? Maybe I can run some GFO short term to capture the excess nutrients and it will have a difficult time coming back. I tested the water before I did anything and got .126 ppm phos through the Hanna ULR checker and corroborated that level with a Red Sea phos colorimetric test. I had fed a large batch of reed roids that day and it likely that spike was the result of the reef roids after I thought about it some more. I ran GFO for 3-4 hours and phosphate dropped to .104. Now I got thinking, this might be a good opportunity to see if Nitrates drop a bit over the next couple days since phos before this has been zero. It would be great to get nitrates to 2ppm and they don’t seem phos limited anymore.

9/15/2020 @ 10:30: .107 ppm
9/15/2020 @ 17:34: .03 ppm
Feeding 1.5 frozen cubes and 1/2 teaspoon of reed roids @ 18:00
9/15/2020 @ 18:44: .034
9/15/2020 @ 21:13: .052
9/16/2020 @ 08:27: .113

Is this normal for phosphate to fluctuate like this?
What is using it so quickly tht carbon dosing doesn’t seem to move my nitrates?

I figure if the 16:1 ratio is a decent guideline I would see atleast roughly 1 ppm drop in nitrates. That could just be a colormetric issue I guess.
Any advice on proceeding from here?

2. If phosphates weren’t the issue regarding lowering nitrates, then is there another limiting factor? I am dosing 5ml daily at 60 gallons.

 

[chipmunkofdoom2]

Ignore the Redfield ratio. It's not useful for our purposes. The only thing aquarists should take away from Redfield's work is that reef aquaria need more nitrate than phosphate. It shouldn't be a target or a goal.

Your dissolved nitrate and phosphate are fine. They're not too high or low. Phosphate will vary throughout the day as you feed. When the food breaks down or the animals in your tank eat and excrete waste, your PO4 will go up. It will trend down again as animals use it or it binds to aragonite. PO4 is likely not the cause of your troubles.

How old is the tank? Did you start with dry rock? I would suspect your tank is still maturing. Either that or you're burning your corals with too much light, which can happen with today's LED lights. Do you measure PAR?

 

[ReefHunter006]

Ignore the Redfield ratio. It's not useful for our purposes. The only thing aquarists should take away from Redfield's work is that reef aquaria need more nitrate than phosphate. It shouldn't be a target or a goal.

Your dissolved nitrate and phosphate are fine. They're not too high or low. Phosphate will vary throughout the day as you feed. When the food breaks down or the animals in your tank eat and excrete waste, your PO4 will go up. It will trend down again as animals use it or it binds to aragonite. PO4 is likely not the cause of your troubles.

How old is the tank? Did you start with dry rock? I would suspect your tank is still maturing. Either that or you're burning your corals with too much light, which can happen with today's LED lights. Do you measure PAR?

The tank is 9 months old. I started with dry rock and coraline only started to grow with any consistency in the last three months. I am waiting for my reef clubs par meter to be available. How long should new sps frags spend towards the bottom of the tank?

 

[Backreefing]

My 90 gallon has ALOT of similarities with your aquarium.
But you are in error to state phosphatescan’t be what’s wrong. They are very important indeed. Mine are a bit more stable ( a little ) and my sps are failing to.
Before all this , I thought man this is easy , what’s everyone’s problem? Now here I am.

 

[Aqua Man]

Try testing for PO4 at the same time of day, everyday. Get a baseline. IMO, before feeding and at least 2 weeks of testing to see exactly where your tank is at.

Also the Hanna can be fickle. Vial needs to be super clean. Vial Placed in the exact same way every time. I line up the H with the B in ppb on the front.