Phosphate 0.104 ppm

kevin_e · Feb 9, 2019

High enough to contribute to STN?

EmdeReef · Feb 9, 2019

Unlikely phosphate would cause tissue necrosis.

Post your other parameters, light, flow, inhabitants to try to figure out.

Justfebreezeit · Feb 9, 2019

As long as its fairly stable it shouldn't.

kevin_e · Feb 9, 2019

What I have tested thus far:

Salinity: 1.026
Alk: 9.5 dKH, 3.4 meq/L, 171 ppm
Calcium: 390 ppm
Phosphate: 0.104 ppm
Temp: Consistent daily range of 78-80

It is a 50 gallon cube. I have a 6 line, an anthias, chromis and a watchman goby. Flow is 2 MP10s. I run carbon and a skimmer for filtration. I run a CO2 scrubber off the skimmer intake that is also plummed outside.

Only other variable I can think of as being a problem is the light. I run a 400 watt phoenix about 18-24" off the surface. But I've been running that since the tank started and set it using a PAR meter.

Acroporaaddict · Feb 9, 2019

What's your nitrate? Are the acropora pale? I was unaware of a 400w Phoenix. I was under the assumption they were only produced in 150 and 250w variants. What par levels did you measure in the tank? Honestly, 400w seems like overkill in a 50cube. I'm running a 250w radium, 4 t5s and a reefbrite on my 50 cube and I'm getting 400 par at the top of rockwork

marlinmon · Feb 9, 2019

Acroporaaddict said:
What's your nitrate? Are the acropora pale? I was unaware of a 400w Phoenix. I was under the assumption they were only produced in 150 and 250w variants. What par levels did you measure in the tank? Honestly, 400w seems like overkill in a 50cube. I'm running a 250w radium, 4 t5s and a reefbrite on my 50 cube and I'm getting 400 par at the top of rockwork

9.5 dKH maybe he's running high NO3?

kevin_e · Feb 9, 2019

Acroporaaddict said:
What's your nitrate? Are the acropora pale? I was unaware of a 400w Phoenix. I was under the assumption they were only produced in 150 and 250w variants. What par levels did you measure in the tank? Honestly, 400w seems like overkill in a 50cube. I'm running a 250w radium, 4 t5s and a reefbrite on my 50 cube and I'm getting 400 par at the top of rockwork

Sorry, its a 400 watt Hamilton. My old tank ran 250 watt Phoenix. I dont have a nitrate test. But yes, mostly pale until recently, where they started to stn.

And I agree, it is overkill, but it is what I have.

kevin_e · Feb 9, 2019

marlinmon said:
9.5 dKH maybe he's running high NO3?

I'm going to assume that my nitrate is high with where my phosphate is at, but I don't have a test. How do nitrate and alk interact?

Acroporaaddict · Feb 9, 2019

I would be willing to bet with a dkh of 9.5 and pale acropora, your Nitrate is actually on the lower side. I would recommend getting a nitrate test kit or seeing if a LFS or local reefer would be willing to test NO3 for you

Acroporaaddict · Feb 9, 2019

Pale followed by tissue recession usually point to starvation to me. You have a reasonable level of PO4 so that would leave NO3 as the next thing I'd personally check

kevin_e · Feb 9, 2019

Acroporaaddict said:
I would be willing to bet with a dkh of 9.5 and pale acropora, your Nitrate is actually on the lower side. I would recommend getting a nitrate test kit or seeing if a LFS or local reefer would be willing to test NO3 for you

Could that combination contribute to STN? I'm a little surprised that phosphate would be high and nitrate low.

Also, and maybe it is unrelated, I have never had any coraline growth in this tank. Really no growth of anyting at all outside of minor encrusting for a brief period. This tank has been up since Nov. 2017.

Justfebreezeit · Feb 9, 2019

kevin_e said:
Could that combination contribute to STN? I'm a little surprised that phosphate would be high and nitrate low.

Also, and maybe it is unrelated, I have never had any coraline growth in this tank. Really no growth of anyting at all outside of minor encrusting for a brief period. This tank has been up since Nov. 2017.

Your tank could be nitrate limited, that would cause your PO4 to be higher than normal as bacteria, algae, and corals need both to grow. Without nitrate they wont uptake phosphate either.

kevin_e · Feb 9, 2019

Acroporaaddict said:
Pale followed by tissue recession usually point to starvation to me. You have a reasonable level of PO4 so that would leave NO3 as the next thing I'd personally check

And I'll clarify, the STN didn't start from the base or tip per se. Just slowly melted away randomly.

kevin_e · Feb 9, 2019

Justfebreezeit said:
Your tank could be nitrate limited, that would cause your PO4 to be higher than normal as bacteria, algae, and corals need both to grow. Without nitrate they wont uptake phosphate either.

Interesting point. Thank you. So it seems I need to get a number on my nitrate. Whats the best kit? I'll be honest, I never really cared to test for nitrate as I did not trust the kits or my eyes to distinguish the differences. That's why I dont have a kit or really any desire to purchase one.

kevin_e · Feb 9, 2019

In the mean time, would anyone suggest water changes to help lower dKH, under the assumption that I'm limited on nitrate?

Ling_Thing · Feb 9, 2019

I would hold off on dosing anymore alk and let it drop naturally to around 8 and then try to get those nitrates up to atleast 1-2ppm dose n03 if you really need to kinda sounds like it

1Blazer · Feb 9, 2019

As helpful as water changes are - I would be more concerned with having traceable nitrates as others have mentioned. Water changes never have hurt in my experience but I do think you can save yourself the headache if you get it tested. One other question--- I personally dont run carbon that long if ever on my sps tank - in my experience it can strip the water and can cause other issues to occur. in short--- I use it sparingly.

Justfebreezeit · Feb 9, 2019

The Nyos or Red sea pro are the two test kits i've used that I like. I would't do much of anything till you test and see if this is even the problem. It very well might not be.

kevin_e · Feb 9, 2019

Ling_Thing said:
I would hold off on dosing anymore alk and let it drop naturally to around 8 and then try to get those nitrates up to atleast 1-2ppm dose n03 if you really need to kinda sounds like it

I actually don't dose alk. Never have had the need to with this tank.

kevin_e · Feb 9, 2019

1Blazer said:
As helpful as water changes are - I would be more concerned with having traceable nitrates as others have mentioned. Water changes never have hurt in my experience but I do think you can save yourself the headache if you get it tested. One other question--- I personally dont run carbon that long if ever on my sps tank - in my experience it can strip the water and can cause other issues to occur. in short--- I use it sparingly.

It is actually time for me to swap out my carbon, but maybe I shouldn't?

I have some minor brown algae that seems to come in waves, probably from the phosphate? Nothing major, just a dusting on glass etc. No hair, no bubble, no cyano or anything like that.