SPS receding from the bottom up

[fin mike]

Does anyone know what would cause some of my SPS to recede from the bottom up. Not all my pieces are doing it, but some are. I can't see any pests munching on the colonies or frags. I recently upgraded my lighting from a Reef Breeders to two Mitras and have finished an acclimation period from 45% to 60% over a months period. Could that have done it? Also, my Alk spiked to 12 dkh a few weeks ago, but I have it down to about 9-10 dkh now. Ca+ is about 425 too. Nitrates at or near zero and Phosphate is undetectable. I also switched out my MP40 for a Gyre 250.

There are a number of variables at play here, so I know it may be difficult to pin something down.

Any ideas?

 

[bios]

Pics will help

 

[Abhishek]

You have the anwser - Alk spike is most probably the culprit.
Could you post some pics ? Is it loosing tissue like RTN or STN ?

It happened to me for one wild tortusa when the Alk spiked to over 8.3 instead of 7.8-7.9 that I normally keep . Brought it down over the next few days, didn't touch the frag as sometimes handling in stressed situation does more damage.
Once the alk was down over the course of few days, STN stopped. Then i took it and fragged it over the dead tissue and attached to a new plug . Looks better now .

Regards,
Abhishek

 

[fin mike]

It's definitely not RTN. It has been happening over about a 4 week period. The corals pictured are the same, just two different colonies. Some other frags/ mini colonies have been doing it too. A monti digi can also be thrown into the mix.

 

[themcnertney]

Alk is most likely your cause for receding.

 

[alten78]

High Alk + zero nutrients = bad times. Those all look extremely underfed.

 

[bios]

Agree with dan Alk lights and low nutrients

 

[aaron23]

salinity / how old are the bulbs and +1 on the alkalinity

 

[fin mike]

I just checked my specific gravity and it's 1.020. It might be a little low. A few other tid bits. Most of my frags seem to have browned out a good bit and their polyp extension, even at night, has been very poor. Alk and Ca+ consumption has dropped off too. The alk spike combined with the new lights I think has done a number on my little pets.

 

[Csreef]

Have you added anything from Australia lately? I'd recommend an interceptor treatment. There was a bug that only came out at night a was eating corals from the bottom up. It was about the size of a red bug. Try fragging the dead part off the colony and if you have them, they'll eat at the next portion of the corals. They hide in the rocks during the day. Good luck.

 

[fin mike]

New GHL mitras

 

[themcnertney]

Alk is most likely your cause for receding.

Salinity and new lighting as most have said. Seems like you got your work cut out for you in a variety of different areas. Good luck, keep us posted.

 

[fin mike]

I feed heavy. Twice daily. There's 12 fish in that tank.

 

[aaron23]

I just checked my specific gravity and it's 1.020. It might be a little low. A few other tid bits. Most of my frags seem to have browned out a good bit and their polyp extension, even at night, has been very poor. Alk and Ca+ consumption has dropped off too. The alk spike combined with the new lights I think has done a number on my little pets.

only a little low? I keep it at 1.025-26

 

[aaron23]

without keeping salinity where it should be, alkalinity/calcium certainly are not where you want it to be.

 

[alten78]

I feed heavy. Twice daily. There's 12 fish in that tank.

Look into manually dosing nitrate to get detectable numbers at the very least.

Low sg, no no3 and po4, high alk...fix those, slowly, and you'll be in good shape.

 

[Abhishek]

Well as others mentioned , quite some to fix .

I would look into bringing in sg to 1.025 , bring alk 8-9 and keep it stable , look into nitrate dosing to bring it to 2-4 ppm and reduce light intensity for the time being .

I personally would avoid dragging anything now before you stabilize the system as the corals are already stressed ..

Once system is stabilized we can look for pests like red bugs and AEFW but system stability is ghd higher priority .

Regards,
Abhishek

 

[fin mike]

Thanks guys. I appreciate everyone's input.

 

[fin mike]

Wanted to give everybody an update. I tested my water tonight and have the following values. NO3 0.0, KH 9.9, Ca+ 470. I only tested those three as those are the only important ones right now. I'd test po4, but I run GFO and it's going to be zero. I slowly brought my sg to 1.024. I also did two fifteen percent water changes since my last post.

I wanted to give you guys some further facts. My corals are still receding and I've lost a few more frags unfortunately. My cheato has been growing hand over fist. My pH has been stabilized better than it ever has. My temp has been very stable too. My fish are pretty healthy and I have 12 of them in a 120. I feed twice a day and I feed them pretty liberally but not excessively. I run my skimmer 24/7 and the photo period on my sump is from 6pm to 11am. I run my top off through a kalk stirrer which I am replenishing with 1 tbsp of kalk every week which is pathetic especially considering replenishment rates of the past.

Here is what I think is going on at this point. I know some of you are thinking "DUH", but hear me out so you can follow my logic. I've been convinced that there is a limiting factor in this tank. Something was either munching on my corals (which there is no evidence of) or the limiting factor was the cause of the recession of tissue. I never thought the limiting factor was going to be nitrate. It's the only thing that makes sense at this point. If there is no fertilizer to make the corals grow, then KH is going to be high and Ca+ is going to be high especially since my input of kalk has been so minuscule. There's no uptake because the corals aren't growing . I've got to get my nitrate up.... now how do I do it without overdoing it.

My plan is to cut that photo period back on the sump. Clearly that cheato is out competing the corals for nitrate and immediately locks it up. That's why its growing so much and the corals are not.

I plan to feed more. I am going to feed three times a day. I am also going to feed the corals, but they never extend their polyps anymore, so I'm not sure how effective that is going to be.

I'm not planning on cutting the skimmer back yet, but I may if the other methods don't work. It is oversized for the tank.

I am going to cut my light intensity back to 55% from the 65%.

Until I get the nitrate issue under control (ironic since when someone makes that statement it's usually because they are too high...not too low) I'm not going to easily get the KH stability under control and the recession issue to end.

In the past, I always had high nitrate and my corals grew like gang busters. It was always algae growth I feared would kill the corals. Oh how this drips with irony!

Any other suggestions?

 

[IronVulture]

Have you considered sending off a triton test to check for any metals in your water.