Is my sponge dying?

[FalsePerc]

Hello, ReefCentral! It's been a while since I've signed on here, as I was forced to get rid of my aquaria when I left home for university. Now, as a graduate student with a passable income, I've jumped right back into the hobby. I look forward to participating in this wonderful community once more!

However, right now (at 3am), I must urgently appeal to RC's body of knowledge. About 2.5 months ago, I purchased a small red/orange sponge from a local shop (I will not attempt to identify its species, as I have read Dr. Shimek's Reefkeeping article on the topic and am convinced it's impossible). The sponge seemed to do very well for a long time, but recently I splurged a bit on frags and was forced to relocate the sponge. Since then, it appears to be covered in a grey/off-white, sandy "film". This concerns me greatly, as I know that a dead or dying sponge can do a number on a 28 gallon reef in no time at all. Despite the alarming film, the sponge appears to be extending its feeding apparatuses from its many holes, which I cautiously interpret as a good sign. I've attached a photo for reference.

Does anyone know what this film is? Would it be best for me to dispose of the sponge now, or wait and see? I am in lab from 8am to 7-9pm every day, so I will not be able to check in on it at regular intervals.

Thanks for reading. I'm really hoping someone here knows what's going on!

Mike

http://img.tapatalk.com/d/14/03/18/hyqu4aza.jpg

[FalsePerc]

It is in a region of easy accessibility/observation right now, with a respectable amount of current passing over it (those zoanthids are always being fluffed by the water flow). It's about 2 feet below some powerful LEDs that keep SPS and clams happy and colorful, however it has always been under this lighting and has never seemed to have a problem.

[Calappidae]

What are you feeding it? Water parameters?

[FalsePerc]

Water parameters are stable:
Ca++ 400 ppm
Mg++ 1400 ppm
Alkalinity 9.5 dKH
pH 8.2
Temperature 79-81 Fahrenheit
Nitrate 0 ppm
Phosphate 0.25 ppm

I feed the tank with Reef Nutrition ArctiPods, and was considering buying oyster eggs. There are many other sponges growing naturally in the tank (and very quickly!) so I thought this one would be a safe bet. It's even grown about 20% since I purchased it.

[FalsePerc]

Forgot salinity! 1.026 (refractometer); maintained by an automated topoff system & very stable

[Calappidae]

Does this film come off? I know algae just loves to choke to a sponge.

[FalsePerc]

I haven't tried to remove it, but when it first appeared I places the sponge in a very high turbulence area, and this removed the film completely. However, the sponge ended up getting picked on by an adjacent mini carpet anemone so I thought it best to move the sponge back to the sand bed where it was previously thriving

[FalsePerc]

Also: aside from a bit of brown slime on the sand bed, this aquarium has never had a problem with algae (knock on wood!) Here is a picture of the tank at this moment, for context:

http://img.tapatalk.com/d/14/03/19/yse8asuv.jpg

Mike

[Calappidae]

I'd try to somehow move it into more flow away from the carpet. If he's growing and behaving normally like describe there is nothing wrong with him. However the algae will kill him soon enough.

I see diatoms and either that's macro algae in the middle or hair algea? Either way you still have an algea problem.

[FalsePerc]

That's some shaving brush macroalgae that tends to do very well in my tank. I also have a bunch of Gracilaris red macroalgae. Apart from a very small amount of brown diatoms (looks more slimy to be honest) on the sand bed, the tank seems to be incredibly resilient to algae growth. It is hands-down the most algae free setup I have ever maintained!

The film on the sponge appears to be more of its own production, rather than algae growing on top. However, perhaps I will take a small sample into lab tonight or tomorrow to examine under high-powered microscope. Would it be a bad idea for me to take a small cutting of the sponge for this purpose?

Also: how strong of a current am I aiming for for the sponge? The location he's in now certainly has very vigorous waterflow.

Mike

[FalsePerc]

The primary reason that I'm so concerned about this film on the sponge is that I remember reading somewhere that sponges will sometimes develop a crazy two white film, and that the author had never seen a sponge coming back from such a state. I also read that a dead or dying sponge can quickly pollute an entire tank with toxins.

[FalsePerc]

Gray to white film** gotta love iphone dictation

[Calappidae]

One thing I know is they cannot be exposed to air so maybe it's best to leave it in the tank rather than take it to the lab.

They do need strong flow, I don't know what exactly would be consitured strong in GPH but going by this source they need medium-high water flow.
http://www.liveaquaria.com/product/prod_display.cfm?c=497+527+574&pcatid=574

My bad with the hair algea. :D

Might wanna deal with those diatoms ASAP tho as they'll choke out your corals and eventually the being in question if not taken care of.. learned that the hard way.

By chance how new is this tank?

[FalsePerc]

Wow, I just did the math and I realized this tank is 8 months old already! It's gone by fast!

I'll certainly look into getting rid of the diatoms (are diatoms "slimy" when they mass?), but they've been there for a few months now and haven't spread anywhere else. The sea cucumber seems to keep them in check inadvertently by eating the sand. You say you learned the hard way - what happened and how did you finally solve the problem?

I am certain that this sponge has not been exposed to air - I got it at aqua hut and the guys there were very emphatic / careful about this. If I were to take a cutting I'd do it underwater. My scope is designed to study living neurons in acute brain slices, so it has its own circulatory system and a submersible objective that I could use to keep the sponge's tissue submerged.

I guess more generally my question is: does the film mean the sponge is dying, and if so is it beyond help?

[Calappidae]

I don't think the film means it's dying. If a sponge was dying it'd shrivel up and have a "tore up-ish" look. If it's coming off in high flow then it's either something it's doing as a stress response from low flow or algae that dislikes high flow is thriving on the sponge.

IME I had hitchhiking sponges I wanted to keep, and a diatom outbreak choked them all out. Who said I resolved it? It's been an ongoing battle for 6 months in all three of my tanks.. (cyano in one.. bryopsis in one, and diatoms+film in the other.. I finally killed all the dinos and they stop growing in the 125.. but bryopsis took it's place) I need a better RO.. and skimmer.

And that looks like diatoms to me. If you can lift it all up like a carpet then it's cyano possibily.

[FalsePerc]

Thanks for the advice. I'm going to find the sponge a spot in higher flow and see if that helps. I'll also try to remove some of the film manually but it seems to be pretty resilient. I do hope it's not algae; I've been so happy that this is the only set up I've had that hasn't had a huge problem with the stuff. Though I suppose that's just part of the hobby..