CUC members dying and Bryopsis?


New member
This week I lost my Fighting Conch and then tonight I found my emerald crab dead. The Conch just kind of stopped cleaning randomly one day and died the next day. The crab had been turning paler and paler but we thought maybe he was going to shed....wrong.
Before I found the crab I brought home 4 more snails but they are doing awesome and all over the glass eating...

I dont seem to have much in regards to algae... just some film algae in the bottom & corners of the glass. Also some spots of rly dark green/brownish furry/fuzzy looking stuff. But what I seem to have the most of is this greyish ashy looking stuff. I had been taking a toothbrush to it here & there but it does come back & nothing seems to be eating it. It looks like dead hair algae that needs to be cleaned off but....? Its really ashy looking which is really weird to me....someone told me it was bryopsis....what do ya think?? Difficult to get a shot of.

I havent done any water testing (besides with a couple strip tests I had leftover from a while ago...normal results) recently but will definitely do so tomorrow evening. All coral looks happy enough and the other CUC members seem normal and the fish are good too. Do you think they couldve starved even tho I get diatoms and some very difficult to remove film algae....


New member
I would deff do some water testing and see where your Nitrates, nitrites and and everything are at. usually i say the first sign of some bad water is when the snails and inverts start to randomly die off.


New member
How about the gray dusty/ashy looking hair algae stuff? Any ideas folks? Nothing seems interested in eating it.


New member
LOL karl! I knowww! I will get some pix tonight. I am doing a wc tonight cuz i just tested trates and they are skyrocketing again :(

**edit: i CANNOT WAIT to get out of this biocube and into a 40B where i can get better flow & dont have a back chamber to gather all the crap!!

CT Reefer

CTARS Member


Hi there. Bryopsis is a feathery and usually green. It is a nasty, nasty algae. If you discover you have it...I would not move any of your live rock from your cube into the larger tank if you can avoid it. Even if you scrub and manually remove it, if you miss one hair...its all over the tank again. Here is a link to a pic of it in an earlier RC thread.



Grizzled & Cynical
Few observations on CUC:

1. Snails are generally quite short-lived, so they do need to be replenished periodically
2. Hermits get picked off gradually by fish, other hermits, etc. - particularly as they molt or move shells.
3. Conch can be tough to keep because most sand beds fail to provide adequate nutrition
4. Got to have decent algae growth in your tank otherwise CUC dies!
5. IMO, most places who sell CUC significantly overestimate requirements - I generally cut it in half.

All that to say that annual, or so, CUC replenishment is likely required