Algae ID ?

Yup, those are dinos, sorry. No light at all helps set them back.

 

I think its cyano bacteria it usually only shows up if you have high nitrates and phosphates check your water parameters

 

Does it look like little balloons on strings at the end of the day? Is it better in the morning than it is in the evening? That's what dinos looked like in my tank when I had them.

 

It looks very similar to what I had last march when I started adding vinegar to my kalk topoff. I also feared Dino's, but I believe mine was some sort of bacteria, like cyano on steroids. Is it on your sand as well?
My alk also dropped low at that time which I suspect had something to do with it.
The bad news is my corals became unhappy and closed up, all but the Duncan, ultimately i only lost a small sps frag ( i think it was called a purple nana). After it went away and everything recovered from the ordeal.

I used kent phosphate sponge and I would blow it off of my rock every day, only to have it come back by morning, eventually I decided to let it burn itself out. It got so thick on the sand i could lift it off like a pudding skin.
When it started to clear I added 15 nasirius, 10cerith snails, 6 hermits, and a fighting conch to help keep everything a little cleaner. I've had no outbreaks since. It lasted 3-4 weeks.

Prior to that I only had 8 small turbo snails in my 75 and my tank was about 6 months old.

 

I had it a couple of years ago and was told by an experienced guy on here (no names) to shut lights off a couple days and did. It took care of the problem.

 

And increase water movement

 

Cyano bacteria. Try to syphon out as much as possible. Since you don't know what your nitrate and phosphate levels are, I'd do 2 50% water changes over 3 days since it's only a 20g tank. If it's possible, I'd take the rock and corals out and swish them in the water you have syphoned out from the WC's to get as much of the cyano off them and out of the tank. Then I would do 3 days with lights out to ensure that it is completely gone. The corals and fish will be fine:=0) Hopefully you have stopped feeding so heavy/DesktopModules/ActiveForums/themes/_default//emoticons/smile.gif

Lastly, you can still use chaeto as a nutrient export method /DesktopModules/ActiveForums/themes/_default//emoticons/smile.gif You can float it in the tank but, an easier way is to use one/more of those large suction holders found in the bath department at WalMart. I think they are for holding soap, shampoo, etc. They have holes in them so there is constant water flow through them. Just every-so-often turn the chaeto for lighting needs.

A queen conch snail will eat cyano but you would need an army of them right now/DesktopModules/ActiveForums/themes/_default//emoticons/smile.gif The conch is good to have to keep the sandbed turned over but they can get rather large ...you would want to ensure your rock is stable and secure /DesktopModules/ActiveForums/themes/_default//emoticons/smile.gif Personally I use the super tonga nassarius snails for my sandbeds.

 

Bring it up Lee I work all weekend. Can test most common things, trates, trites, ph, alk, calc, phos. Looks like a type of cyano to me. Expect to see you this weekend now. /DesktopModules/ActiveForums/themes/_default//emoticons/smile.gif