Everything is Dying

I have no idea what's going on with my tank. Everything has been really happy, growth has been great tank is about 10 months old. Three days ago, the duncans were all closed up, then the frogspawn all closed, now all the sps don't have any polps out and some are starting to brown out. The clam is shut, had 1 peppermint shrimp die and some snails. The gold torch isn't fully extended and the lps don't have any feeders out like they normally do (except the acans and chalices seem normal). The fish all act fine and don't show any strange behavior.

The tank is a 3x2x1 bare bottom frag tank (that I use as a display tank) and has a 20 gallon sump as well in which is macro algae and a bunch of live rock. I run a combo halide T5 lighting and a skimmer with a filter sock. I change the filter sock twice a week, do 20% weekly water change (I use Red Sea Coral Pro Salt Mix and always use RODI water).

Here the tank livestock:

2 snowflake clowns
2 black and white clowns
2 anemones
1 yellow tang
1 bangaii
1 small hippo tang
1 cleaner shrimp
1 peppermint shrimp (left)
A variety of lps and sps corals

I ran tests last night (I use Hannah testers)
Alk - 10.7
Calcium - 400
Salinity - 1.024
Temperature - 77 degrees F
Nitrates (API tester) - 20
(I doubled checked my RODI and it's 0 tds)

I've heard the API testers tend to run high and aren't accurate under 20, but that still is really high. I'm wondering if something could have caused a Nitrate spike.

So, there have been two things in the tank that have changed.

1. I noticed a few flatworms on the glass. I treated with flatworm exit that I had, but after a day, the flatworms were still there, but I didn't have any more so I picked up some Flatworm Solution from aquatic dreams and treated with that. That took care of the flatworms. I did a water change the next day. It was about 2 weeks later that the stuff started dying.

2. I pick up a small orange sponge about the size of a quarter in diameter and two to three inches long. It became dislodged sometime and I'm guessing got chopping up in the power head because it is no where to be found. It was the next day the tank started going down.

So, do sponges release toxins? I've read yes and no. Or maybe the sponge dying is why the nitrates are high? It wan't a very big piece of sponge though. If it is that, could an unseen piece of sponge still be in the tank causing the ongoing problem?

Could the flatworm solution have killed up the good bacteria so the nitrates started building up and the sponge deal just pushed it over the edge? I did a 50% water change yesterday and started running carbon, but there is no improvement today.

It's so sad to see everything going down hill. Help save my tank!

Probably, but if I understand correctly, when flatworms die, they secrete iodine which is the toxin. That would have ill effects immediately not several weeks and multiple 20% water changes later, right?

Flatworm exit does kill more microfauna than flatworms. Maybe that is part of the problem. I would also check salinity.

Mike is right on.  I would do another w/c and get carbon in there asap.

I wouldn't add anything personally.  A 50% waterchange will drop nitrates in half alone.

I'm thinking nutrients. I use Prodibio for bacteria. What test difference do you see before and after a water change?

The tank 5 days ago...





The tank now...

Frogspawn




Torch



Duncans



Duncan Yesterday



Not sure what this is but it's gone brown.



JF Jingle Bells (browned)



ORA Spongode (browning)



Birdsnest (No polyp extension)



Poci on Right has not polyp extension and the ever durable been through everything orange digi has no polyp extension



Green Slimer (brown no polyps)



The acans still look good



You get the idea...all the SPS have 0 polyps out.

Edited by Hogie - March 04 2015 at 12:02am

It's later. 

Food for thought. 

I have always done weekly 20% water changes. Never had any problems. I do mix my salt for at least a day though, and make sure salinity and temp are perfectly matched to my display.

I always run carbon, always have, always will.

If you do a larger water change, then run some carbon and phosban your issues will clear up.

Sps will likely take a while to get it's color back.

Edited by Pete Moss - March 04 2015 at 9:48am