Heavy metals possibly? Suffering Hammer and Torch

[dhalderman]

I have a 70 gallon mixed reef.
Corals:
Hammer
Torch
Encrusting Montipora (red)
Seasons greating montipora
Branched montipora
Pocillopora

Fish:
Yellow tang/Potters angel/2 clowns/tailspot blenny/firefish/3 green chromis

And a Blue Maxima Clam

Everything is generally flourishing looking great. Hammer and torch, the subject here, were completely extended, great color and looked very happy. Seemingly overnight, the torch and hammer became retracted to only about 20% their normal extension, with part of their skeleton even showing. Parameters remain unchanged. Keep in mind these corals are not new, Tank is about 17 months old and these corals have been there for about a year. The Hammer, went from a single head to the current 8 heads, excellent growth. So now, with virtually no change, it seems to be suffering. There is one thing I realized that happened but im not sure if this is possible so this is essentially my question. I lagged one time and the sump water level dropped low enough that the heater was exposed.
The heater I have is here....
https://www.amazon.com/dp/B002TMMSU2...487742019&sr=1
Being exposed to air it became very hot and burned off the chrome finish, turning it to look like a dirty, burnt looking metal. Could this have released heavy metals into the tank that are hurting these corals? I have since changed the heater once I made this correlation, albeit pretty late, so I guess im gonna find out one way or another as I do water changes now. What baffles me is my SPS and clam look great. But LPS suffering. And there is no other changes I can find. Corals have lived in this exact environment for a year looking great. Thanks for any help!!

[bertoni]

I'd probably replace the heater and run a PolyFilter for a bit, but I'm not sure that's the problem. If any animals were added recently, the issue could be a disease or predator.

[dhalderman]

Thanks for the reply bertoni. I haven't been able to put a poly filter in but i've run some carbon and done a couple water changes. Hard to say if there is any change. They might be a hair better but this could be normal fluctuation. I have kept my eye out but haven't seen anything messing with these corals, so if this is the problem it will be a difficult one for me to solve : (
Hanna phos checker reads 0. Salifert nitrate test also reads 0.
My pH is 8.1 pretty consistently, had been that since I started the tank. I keep the alk about 9-10.
One other possibility, (as I rack my brain for changes), is that I changed my light, from a aquatic life XS UV to my current light, a kessil ap 700. But the change in coral did not happen until approximately 4-5 weeks after the light was up and running, so my mind did not immediately go to that. Based on that, IF IT IS the light, do you think the problem would be most likely too much light or not enough? Thanks again.

[bertoni]

My first guess would be too much light, but I agree that it's strange that the changes started weeks after changing the setup.

[dhalderman]

Alright thanks. I will update this thread after the next couple water changes. Going to do them a little sooner than I usually would. And probably wont mess with the light 'till I see what the water changes do. Try to do this scientifically and narrow down what the actual problem is. If the WC's do nothing, I'll begin fine tuning with the light.

[Vinny Kreyling]

What are your Calcium & Magnesium levels?
Nitrates are now considered to be beneficial @ 5 -10 PPM.

[dhalderman]

I'm thinking you're onto something Vinny. I used to spot feed my euphyllia but they were doing so great I figured hey, less work same results so i'll stop, plus most forums on the subject state there is no need.
The change happened a month or 2 after that, and it also hasn't grown. Keep in mind the hammer went from one little head to 14 and had 100% beautiful PE the entire time. 2 months or so after I stop feeding it hasn't extended past about 30% PE and hasn't grown a new head.
This was also the same time it grew far enough out that it was more in the current, and also the same time I bought a new light. So I had 3 possibilities, light, flow and feeding. Tried everything I can think of with the light and no change. Most say they can do many light variations anyway. Also lowered the flow which looks much more appropriate now but still no change.
I do think my system is extremely clean (too clean) and no test at any time has given me anything other then zero, with regards to Nitrate and Phosphate. Using API, Salifert, and Hanna Phos checker throughout the 2 year life of my tank.
Having said that, and assuming this is the problem.......
1) Would you expect spot feeding to correct?
2) How long with feeding should I expect to see a change if so?
2) How often do euphyllia corals need to be fed? For those that feed theirs.

P.S. Maxima clam and Montipora doing great throughout all of this, growing like weeds, which i'm hoping is a good enough vouch that my water quality is not wacky.

[bertoni]

Spot feeding can help with a lack of certain nutrients, and it also obviously increases the food available to fuel growth. Along the way, it might change coloration. I'd give at least a few weeks to see any possible results, but I don't have any data on the subject. I don't know how often to feed, either, although small amounts daily likely would be the closest to nature.

[Vinny Kreyling]

According to many fish poop is best so keep the fish dare I say --Fat, or @ least chunky.
I let some food land on mine, gobbles up Larry's stuff.

[dhalderman]

Alright thanks for the feedback Bertoni and Vinny. I'm reasonably confident this is the problem. I think it barely has been having enough food/nutrients to survive, so it's not thriving at all, it's "surviving". I hope this is why the PE is poor, and I hope this solves it. Thanks again, i'll probably start another thread for those that feed their euphyllia and see what they say.

[dhalderman]

And for what it's worth, here is a picture. I guess it doesn't look terrible, but this is about 30% of what it used to be. Used to be a giant bush, the separate head were not discernible except for at night.

[bertoni]

Hopefully, more food will help it grow. It still looks like it's healthy. Maybe it's just "skinny" for a coral.