Something's wrong with this one...

[john_1ml]

I’ve had this distinct coral for about 5 weeks, and recently I’ve noticed it’s being covered with a white substance. The white layer seems to adhere to the mushroom-like texture of the coral. I initially believed it to be a red pipe organ coral, but after some research, I couldn’t find a match. Can anyone help identify this coral and suggest solutions to this issue? (Already tried dipping, it made it a little worse)

 

[Derrick0580]

I’m gonna guess red chili coral but I’m not 100% sure

 

[Tuan’s Reef]

Red sponge ?

 

[ISpeakForTheSeas]

That seems to be an ailing Red Tree Sponge (sorry, the info below is lengthy, but it’s my current, compressed version):

Just to comment here, for these specific sponges (Ptilocaulis sp. in this case, though this comment also applies to the Red Tree Sponge, Amphimedon compressa, which is sometimes sold as Orange Tree Sponge as well), they actually do fine in exposed, moderate to brightly lit, shallow waters in nature (though I suspect they prefer low, turbulent flow despite being in relatively open locations). So, I doubt the lighting/algae will be an issue as long as the sponge is healthy (though if it's unhealthy, it's possible it may lose out chemically and succumb to algae).

For most filter feeders you may get, you just feed some phyto and call it good (I'd recommend Isochrysis galbana (T-Iso) at the minimum and adding Chaetoceros sp. and Tetraselmis sp. if you can - adding more from there shouldn't hurt).

For the sponge specifically, they will probably die, yes, but you may well be able to maintain them too. That said, when it comes to sponges, there are things you can do/try to keep them alive. For the super brief explanation, you need the right foods in relatively large quantities, the right flow, and the right elements:

Food/feeding:
-Isochrysis galbana (T-Iso) or a blend of phyto containing it is a good idea.
-Bacteria, Cyanobacteria, Dissolved Organic Matter (DOM), Particulate Organic Matter (POM), possibly Diatoms, etc. are good food for sponges, so things like stirring the sandbed and basting waste off of the rocks in the tank with the sponge may be helpful (I know this may not be possible depending on the tank, but finding ways to get bacteria into the water for the sponge to filter is a good idea).

Your sponges probably won't feed on Reef Roids, as the food in Reef Roids is too big (I've seen it stated at 150-200 microns, most of the food consumed by sponges is DOM, which is smaller than 1 micron; even the larger foods like the T-Iso are only like 6 microns at the largest).

Flow (and Light):
I recommend reading both quotes below for flow.

Most sponges that I’ve looked into primarily consume Dissolved Organic Matter (DOM - sometimes called Dissolved Organic Carbon, or DOC, which is actually a component of DOM) and specific kinds of bacteria (which kinds vary at least a little from one sponge to another). Most of them seem to have no preference for where their DOC comes from, but they have a preference for algal-derived Dissolved Organic Nitrogen (i.e. DON produced by algae). Giant Barrel Sponges and some Boring Sponges have had their diets analyzed, and they primarily consume DOM (~80% of their total diet, with the remaining ~20% coming from Particulate Organic Matter (POM - primarily phytoplankton and bacteria, though, as mentioned above, bacteria is taken in much higher quantities than phyto). This ratio of approximately 80/20 seems to be pretty typical(though it can vary from what I've seen by +/-15% or so one way or another) for most sponges from what I can find.

Flow (and Light):
I recommend reading both quotes below for flow.

If you do some reading on sponge keeping here on R2R, you'll probably find pretty quickly that most people recommend low lighting low flow for sponges (exceptions for photosynthetic sponges), but the truth is this also depends on the sponge species. The most common photosynthetic sponges in the hobby are the photosynthetic plating sponges (like you can find/buy on LiveAquaria's site), but there are quite a few other sponges that are photosynthetic too (such as Aplysina cauliformis, for example), and these would benefit from high lighting. Similarly, some species of sponge do best in very high flow areas, including high flow areas with laminar flow (a lot of people talk about random flow on the site, which would be called turbulent flow, as they're trying to get the water moving basically randomly throughout the tank - laminar flow is just a continuous flow that doesn't change, so the water keeps going the same direction nonstop and there's nothing random about it). If you're not sure if the sponge is photosynthetic or not, you can try starting it in one lighting (such as low lighting), see how it does and then compare it to a different lighting (moderate or high) and figure out its needs from that. Same with the flow. Light will probably be the most important part for photosynthetic species and the food/flow the most important for NPS species - some people have found stirring up their sand to be an effective food source for sponges, likely because it puts bacteria and DOM into the water column. It’s probably safest to start low light/flow and move up, rather than starting high and moving lower.

Should you decide to try and keep any of the sponges you're interested in, take note if you can of the sponge's surroundings and the flow it's in - if you can't do that, the link below may help you figure out sediment and flow preferences for any sponges you want to keep (the graphical abstract close to the top is a visual representation of the info presented).

No taxonomy needed: Sponge functional morphologies inform about environmental conditions​

The need to study sponge communities in comparatively inaccessible habitats led to a sponge classification system that relies on the strictly function…

www.sciencedirect.com

Elements:
Basically, most sponges need silicates, and many need other elements that we don't often test for in tanks - I've heard of people having good anecdotal success with dosing ChaetoGro, so I'd probably recommend that at this point for meeting the other elemental needs of the sponges.