Is this Green Coraline Algae or something else?

[Steve2020]

( History ): I had a Dino outbreak a few months ago and is now completely eradicated . Pods, phyto, MB7 & MB Clean alternating days, along with dosing sodium silicate to get a diatom bloom did the trick along with a top 1/4" sand removal from my 1" sand bed. Diatoms are now gone so I wanted to put my clean sterilized sand back in the tank.

One thing I have always had with my tank is that some areas of the sand is calcified. With my light spectrum, the sand always showed some brown and purple specks on the sand. The purple I assumed was Coraline Algae and the brown I was never sure what it was but it does not blow off and does not come off with a tooth brush so really never paid much attention to it.
So today I decided to run all white light in the tank to inspect to make sure all the dyno was gone and it is but to my surprise what I thought was brown is actually green. It does not blow off and will not come off with a brush. The rock is even green along with some Purple Coraline. Nothing shows up under a scope except for sand crystals. Where the green appears darker is where the sand is calcified.
Is this Green Coraline or something else?

20K light spectrum photos


All white light photos. Magnificent Foxface does not like the white light

 

[Dan_P]

( History ): I had a Dino outbreak a few months ago and is now completely eradicated . Pods, phyto, MB7 & MB Clean alternating days, along with dosing sodium silicate to get a diatom bloom did the trick along with a top 1/4" sand removal from my 1" sand bed. Diatoms are now gone so I wanted to put my clean sterilized sand back in the tank.

One thing I have always had with my tank is that some areas of the sand is calcified. With my light spectrum, the sand always showed some brown and purple specks on the sand. The purple I assumed was Coraline Algae and the brown I was never sure what it was but it does not blow off and does not come off with a tooth brush so really never paid much attention to it.
So today I decided to run all white light in the tank to inspect to make sure all the dyno was gone and it is but to my surprise what I thought was brown is actually green. It does not blow off and will not come off with a brush. The rock is even green along with some Purple Coraline. Nothing shows up under a scope except for sand crystals. Where the green appears darker is where the sand is calcified.
Is this Green Coraline or something else?

20K light spectrum photos


All white light photos. Magnificent Foxface does not like the white light

If I did not read your observations, I would have said green cyanobacteria. The other alternative is a green micro algae. You would need to examine the sand under a microscope to decide what is growing on the sand.
By the way, why does your fish, pictured in the second to last photo, appear to be keeled over on the sand?

 

[Steve2020]

If I did not read your observations, I would have said green cyanobacteria. The other alternative is a green micro algae. You would need to examine the sand under a microscope to decide what is growing on the sand.
By the way, why does your fish, pictured in the second to last photo, appear to be keeled over on the sand?

He did not like it when I switched the lights from a 20K spectrum to all white. He is fine.
Microscope only shows and crystals. Nothing else. I also removed some sand and did a peroxide test and vinegar test.
Peroxide showed no change but the vinegar dissolved the green substance. Not 100% sure what those results mean but I do know vinegar does dissolve Coraline.

 

[Bucs20fan]

When peroxide kills algae its not instantaneous death, it takes some time, then it turns brown or white and decays. Its some form of algae for sure. Much better than dinos! I dont see many snails in your tank, they would much it up fast off of the rocks for sure.

 

[Steve2020]

When peroxide kills algae its not instantaneous death, it takes some time, then it turns brown or white and decays. Its some form of algae for sure. Much better than dinos! I dont see many snails in your tank, they would much it up fast off of the rocks for sure.

When peroxide kills algae its not instantaneous death, it takes some time, then it turns brown or white and decays. Its some form of algae for sure. Much better than dinos! I dont see many snails in your tank, they would much it up fast off of the rocks for sure.

There are approx 35 snails in the tank. When they had babies about 8mo ago I had way more but many have passed due to what I believe was starvation due to the lack of eatable algae in my tank. Most but not all of the snails hang out on the glass and powerhead covers.
Do you think it is ok to put my sterilized sand back in the tank? It will pretty much cover the top of the existing sand in the tank.

 

[Bucs20fan]

Your snails perished from eating dinos, its a slow killer for them and they will eat as much as they can. Thats what happened to your CUC. You can do that, but the algae it traps will decay and be trapped, if you add it, stir the sand up so both layers mix. You dont want all that dead algae trapped with no way for gasses and nutrients to be exported.

 

[Steve2020]

Your snails perished from eating dinos, its a slow killer for them and they will eat as much as they can. Thats what happened to your CUC. You can do that, but the algae it traps will decay and be trapped, if you add it, stir the sand up so both layers mix. You dont want all that dead algae trapped with no way for gasses and nutrients to be exported.

Snails perished months before my dino outbreak. Funny that I did not lose one snail during the outbreak though.
Thanks for your recommendation. Appreciate it!!

 

[Steve2020]

Your snails perished from eating dinos, its a slow killer for them and they will eat as much as they can. Thats what happened to your CUC. You can do that, but the algae it traps will decay and be trapped, if you add it, stir the sand up so both layers mix. You dont want all that dead algae trapped with no way for gasses and nutrients to be exported.

I just took a stiffer brush to an area on the rocks and what ever type of algae it is it WILL NOT scrub off. Any Idea of the type of algae it might be?

 

[Bucs20fan]

I wish I was an algae expert, but im not sure. It could very well be green coralline algae, just it being on the sand stumps me as that isnt typical behavior of it.

 

[Lavey29]

Probably some type of hard film algae. I have it on my rocks. Although coraline can come in different colors of course the purple is predominant and it typically covers plastic parts first like powerheads then moves to back wall and rocks. Not typical at all for the sandbed.

 

[Steve2020]

I wish I was an algae expert, but im not sure. It could very well be green coralline algae, just it being on the sand stumps me as that isnt typical behavior of it.

I actually have Purple Coraline that is on the individual grains of sand also. One thing I forgot to mention is that I normally scrape my glass every 3-4 days but if I wait to long, I get what appears to be the same algae specks and a little film algae on the glass and the film comes off but the specks will not come off with my mag algae scrapper so I have to add the blade attachment to the scrapper to scrape the algae off. It is some tough stuff whatever it is.