Do these ICP results tell why my SPS/LPS is clinging to life?

[FloodWaters]

Stats:

• Nitrates: 15-20ppm (rock stable)
  
  
• Phosphate: 0.199 (65ppb per Hanna checker) [I had dropped it to 0.037 with Lanthanum over the course of 3 weeks during July, but everything just got even worse and cyano was everywhere]
  
  
• ALK: 8.4 (it moves a little between 8.2-8.4 depending on water changes and the doser acting up)
  
  
• Temp: 80-83 ( Closer to 80, but it moves a bit due to stupid summer. I used a Controller with a heater and a fan outlet to manage it as best as I can)

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• I use the blue box of Fritz Salt
• I run a pretty large DIY algae (roughly 12"x20" and lit from both sides with good growth)
• Reef Octopus Skimmer rated for 210gals (150INT)

(I'll update this section if anyone wants to know)



I have been a bit frustrated with one of my systems. It's a 120 with a 90ish gallon sump that has been running for 6 years. The only major change was when I plumbed my 90 gallon into the sump loop last year.

The System:
The 120 is HUGE rock pile covered in mushrooms with 3 large anemones we have named "The Vincents"... it is 100% soft coral, but looks pretty good for what it is.

The 90 was a new experiment with 3 small rock islands, some bargain basement SPS/LPS and a few zoas. It was running for about a 6-8 months before we plumbed it into the larger system.

The Issue:

The coral in question is an blastos, acan, some random $10 greenish/brown acro frag and a purple digi. The acan and digi came from my ~60gal frag system with a blackbox LED (light tunnel?). While in the QT/frag system the acan grew from a 1/4 of a head to 3 heads, the digi went from a stick to a colony the size of my fist. Everything looked healthy and pest free, so I moved them into my 90Gal system and it was like hitting the pause button!

The digi goes from fluffly to slightly dying off in patches and then fluffy again, but it never grows. Everything else in the system is either close to exactly how it was on day 1, or looking worse/smaller.

I was really banking on this ICP to tell me that I have 8000ppm of lead, tin, and screwcoralathum... but the results actually look pretty good other than my low mag... Any insight is appreciated.

 

[Oscar47f]

My best guess if your water is stable and good is your lighting... also that level of nitrates may be too high and the digi hasn’t gotten used to it...

 

[jccaclimber]

I wouldn’t expect 20 PPM nitrate to mess up a digi. What does the tank get fed?

 

[rusgum]

LPS love temperatures of 23/24 degrees Celsius. If you have transferred a large colony of digi, then there is a tissue loss option. I agree that if she lived at low nitrates, then at 20 units there could be consequences. What the ICP showed I would not worry. I would not use lanthanum with the phosphates you had. Any change in the type of KH jump could cause your problems. To the extent that corals go into deep hibernation

 

[FloodWaters]

Update:
10 days later and coral is basically the same. Temp/ALK has remained pretty stable and I have not used any lanthanum. However my phosphates have been on a constant rise and currently sitting at 0.285ppm (93ppb). My bio-load actually went down, due to the death of my Mandarin (He had been full grown for years, so I assume old age).

Feeding:

• Frozen Mysis (Selcon soaked) - I feed every few days, but it used to be daily for my Mandarin. My numbers have been going up with LESS feedings.
• Nori (Selcon soaked) - Half a large sheet of plain from the local Asian market fed daily for large hippo tang, yellow tang and foxface.
• TDO pellets - Fed daily

I used to feed Reef-Roids, but stopped feeding the coral months ago due the phosphate trending upwards.



Observations:
Algae scrubber is growing normally, but it just doesn't seem to be able to put a dent in these numbers

With a total volume of ~300gals large water changes are difficult to say the least. I have been doing 45 gallon water changes when things look even worse than normal, but that doesn't put a dent in my nutrients either.


Possible Options:

1. Add chaeto to the sump

Pros: ​

• Boost my export
• Less chemicals

Cons:​

• I am fairly positive it will bring bubble algae back to system after knocking it out with vibrant last year

2. Do a 50%+ water change

Pro:​

• Should instantly knock down my nutrients

Cons:​

• Probably doesn't fix the root problem
• Expensive
• Logistically different because I don't own a 150gal container and would have to use multiple mixing containers.

3. Go back to dosing lanthanum to try and knock down phosphates.
Pros:

• Definitely removes phosphate

Cons:

• Will probably put my nitrates even more out of balance
• ticked off the tank last time

Any comments or suggestions are welcome because this is turning into a head scratcher.

 

[Randy Holmes-Farley]

I do not have high confidence in this company's capability with respect to ICP, but I agree that I do not see anything dramatic in the results. I doubt the phosphate is the issue either.

 

[jccaclimber]

I’m in favor of options 1 or 3 if you wish to reduce your phosphate. Option 2 sounds inconvenient and short term at best.
I would not worry about the ratio of N. Is there a way to increase output from the algae scrubber? Time, intensity, whatever?

I'm not seeing any obvious red flags.