Growth to RTN

[Waters]

My tank seems to go through cycles, which normally last weeks at a time. I see huge SPS growth with heavy ALK consumption, followed by 0 ALK consumption, and RTN. At this point the SPS either recover and start growing again, or they completely die and I replace them, only to start the whole cycle all over again. I cannot figure out what is causing seemingly healthy Acros to suck up ALK, grow like crazy, then show signs of RTN at the base. Numbers are all consistent other than the ALK rise when everything stops growing (at which point I decrease the amount of 2 part being dosed). If I never showed any growth I could look at the normal voltage, water contaminants, etc. but if that was the case, I don't think anything would grow at all. Nothing has changed as far as my maintenance or dosing routines...has been the same for over a year. Doesn't effect anything other than the Acros....LPS and other SPS appear fine. For reference here are my numbers...

SG - 1.025
PH - 8.1
Temp - 79.4
ALK - 8.4
CA - 450
NO3 - 5
Mg - 1350

Any ideas?

 

[DSC reef]

Are the acros maricultured? Not sure it matters but this is definitely a strange dilemma. I know when I tried maricultured or frags from a wild colony I would get great growth for a bit then over night a white skeleton. Your parameters look spot on.

 

[apt220]

Phosphate?

 

[Waters]

Are the acros maricultured? Not sure it matters but this is definitely a strange dilemma. I know when I tried maricultured or frags from a wild colony I would get great growth for a bit then over night a white skeleton. Your parameters look spot on.

I have tried both aquacultured and matriculated....never seemed to make a difference. Phosphate is close to undetectable but it has always been at that level (even during the high growth periods)....plus I always have some algae growth so I assume there is at least some present.

 

[apt220]

Could it be pests? AEFW? What test kit do you use for phosphate?

 

[DSC reef]

I have tried both aquacultured and matriculated....never seemed to make a difference. Phosphate is close to undetectable but it has always been at that level (even during the high growth periods)....plus I always have some algae growth so I assume there is at least some present.

Same with me, I always keep a little algae around. Nitrates register at 10ppm while phosphate registers 0 on salifert kits. I'm stumped waters, I'm hoping you get it figured out soon my friend.

 

[Waters]

Could it be pests? AEFW? What test kit do you use for phosphate?

Use Hanna tester for phosphates.....pests are possible I guess but I have looked several times and I do not see any evidence. They cannot be dipped since they are all encrusted and cannot be easily removed.

 

[Waters]

Same with me, I always keep a little algae around. Nitrates register at 10ppm while phosphate registers 0 on salifert kits. I'm stumped waters, I'm hoping you get it figured out soon my friend.

Thanks...I hope I get if figured out as well....it is starting to get frustrating when I see a bunch of growth and then spot that first sign of RTN

 

[joeyhatch11]

Thanks...I hope I get if figured out as well....it is starting to get frustrating when I see a bunch of growth and then spot that first sign of RTN

Possibly elevated phosphates. Also triple check your Alk.

 

[nashorn]

Use Hanna tester for phosphates.....pests are possible I guess but I have looked several times and I do not see any evidence. They cannot be dipped since they are all encrusted and cannot be easily removed.

From what I know pest cause a stn rather a rtn but you will see signs of them.
Any old school sps in the Tank?
Temp? 79.4 so maybe over 80+ during the day.

 

[Waters]

From what I know pest cause a stn rather a rtn but you will see signs of them.
Any old school sps in the Tank?
Temp? 79.4 so maybe over 80+ during the day.

No....temp never fluctuates more than .3 degrees. It is controlled by an Apex in a basement, with either air conditioning or heat depending on the season. The tank has a large mixture of everything from Slimers to Pink Tip Paletta. The acros are the only thing that ever seems to have issues.

 

[Waters]

Possibly elevated phosphates. Also triple check your Alk.

I actually check ALK daily now....just to catch possible swings. Phosphates normally read 0 on both the Hanna and Salifert......if anything they are too low but that wouldn't cause RTN

 

[Mattrg02]

Something in the air? Run any activated carbon?

How about your salt mix? I always wonder if settling causes some water changes to have too high/low trace elements?

 

[Mal11224]

How often are you doing water changes. Also, are you dosing and supplements? I used to have such a hard time keeping acros and now I'm doing better at it. I started doing more frequent water changes and lowered my nitrates to about 10ppm and I switched to ESV 2-part and slowed down on using Red Sea ABCD. I think reducing my nitrates and increasing the water changes helped a lot. I am seeing good growth and crusting. I've tried so many things to keep acros and I think this is working for me. Have you made adjustments to your lighting?

 

[Waters]

Something in the air? Run any activated carbon?

How about your salt mix? I always wonder if settling causes some water changes to have too high/low trace elements?

I do run carbon 24/7 and always have. I am also careful to not use any sprays or cleaners in the basement....unless it is something coming from the furnance/air conditioner (which are less than a year old) then I don't think it is anything in the air but at this point I won't rule anything out :-( Regarding salt mix, I had the same issues using Reef Crystals as I do now using Red Sea Blue. I switched over thinking the high ALK with lower nutrients was causing my RTN issues.

 

[Waters]

How often are you doing water changes. Also, are you dosing and supplements? I used to have such a hard time keeping acros and now I'm doing better at it. I started doing more frequent water changes and lowered my nitrates to about 10ppm and I switched to ESV 2-part and slowed down on using Red Sea ABCD. I think reducing my nitrates and increasing the water changes helped a lot. I am seeing good growth and crusting. I've tried so many things to keep acros and I think this is working for me. Have you made adjustments to your lighting?

I change 15 gallons of a 130 gallon system weekly religiously....right down to the same day and time each week lol. Have been doing that for a year and a half. The only thing I dose is 2-part and acropower once a week. I have adjusted lighting but it has been a ridiculously slow process.....only increasing intensity by 1% every two weeks (afraid to go any quicker since I have had these RTN issues over the past year). I am currently only sitting at maximum intensity of 57% using two Gen 3 Radion Pros over a 105 gallon tank.

 

[Mattrg02]

I wonder if you could be running carbon TOO much? I know it takes a lot out of the tank water including some stuff your corals may need?

Also, you might want to try dosing the acropower daily, in smaller amounts. I believe the corals will only take up so much and then the rest goes to algae and bacteria.

No idea on the lighting.

 

[DSC reef]

The fact that there growing and coloring normal then all of a sudden have rapid necrosis has me puzzled. Almost like clock work. I won't rule out pests but I'm not thinking it's chemistry related due to the rapid decline. Normally there will be other signs if the corals are starving, water to clean, ect. Being that it's only happening to acropora and all other corals look good I'm leaning towards pests that can't be seen. Definitely a mystery here @Waters

 

[Waters]

Thanks everyone for the responses.......I will look again for pests. I have spent a fair amount of time with a flashlight but I have not seen anything that I am noticing as of yet. I might also shut off the carbon as Mattrg02 suggested....although it still doesn't explain why I still get good growth at times....the carbon is running then also. I will check the Apex and see if the times that it is changed line up with any of my RTN cycles. I am such a creature of habit it will be tough to not use carbon though I will admit lol.

 

[Mattrg02]

Thanks everyone for the responses.......I will look again for pests. I have spent a fair amount of time with a flashlight but I have not seen anything that I am noticing as of yet. I might also shut off the carbon as Mattrg02 suggested....although it still doesn't explain why I still get good growth at times....the carbon is running then also. I will check the Apex and see if the times that it is changed line up with any of my RTN cycles. I am such a creature of habit it will be tough to not use carbon though I will admit lol.

I'd wait to get some more thoughts on the activated carbon before taking it offline. If that's not the problem, you might upset something else.