Dark green/black algae? Mold? What is this?

[augustus4842]

Hello all! I've had my shrimp tank for about 2.5 years now.
At first I noticed a black spot on the bottom of the tank. Now there's a big blob of black/dark green on the sand substrate. There's also a bunch of teeny little white things on the side of the tank where the moss sits, I'm guessing it's poop?

Background info on my tank:
a little under 2 gallons
Wispy moss
Pieces of coral
14 souls
Have had 4 bunches of berried shrimp, none of the babies have made it beyond 2 weeks
There's currently 1 berried female.
The shrimp are red and happy most of the time
Last time I gave them a little food was a month ago
Per Mustafa's direction, I'm not planning on feeding them for 3 month intervals.

Is this black/dark green stuff harmful? Or is it edible? Should I try to mix and expose the stuff?
What is it?
What should I do?
Am I just being paranoid? I'd hate to see another bunch of babies die off...

[tooth]

I'm not an expert, but I don't think black is ever good in plants--usually indicates necrosis. I'd carefully remove it.

[augustus4842]

Oh no! How would I go about removing it? I really have no other aquatic tools... The shrimp seem to be doing fine.

[Varanus]

Is the black actually part of/connected to the macroalgae plant? If not then tooth may have misunderstood. Your description suggests its not, but the picture is a bit too blurry for me to tell.

It may indeed be some kind of micro algae, in which case you might just observe it to see if it continues to spread or not.

[augustus4842]

At first it formed at the bottom of the glass. It was green, then it turned dark green, and now it looks black. I don't think it's connected to the moss.
It is spreading, but not very quickly.

[Mustafa]

It's probably some type of cyanobacterium. It usually forms when you overfeed and there aren't snails in the tank. If it peels off easily you can try to remove it. Otherwise I'd just leave it there and after a few months without nutrients it will shrivel up and die.

What is "wispy moss" by the way? If it's any kind of freshwater moss that may be one of the reasons for your problems.

[augustus4842]

Thank you for the reply!

The dark seems to form after the shrimp poop. At first it's light brown shrimp poop that sinks below the surface of the sand. Then it turns green, then gets darker and finally looks black. It doesn't seem to be bothering the shrimps, they are red and reproducing. It just looks rather icky against the white sand substrate.

My tank is under 2 gallons. Can it support a nerite snail?

I bought the moss with the shrimp and was assured it was from the shrimp tank. So I'm hoping it is some kind of brackish water moss?

[Mustafa]

I'm not a big fan of nerite snails in Supershrimp tanks as they are voracious eaters and then possibly even lay those hard to remove eggs all over the glass and decoration. But, yes..your tank could support one.

As for the "wispy moss"...if that's the stuff at the bottom of your container in the picture, that looks like plain old hair algae to me. It's usually a nuisance that people try to remove from their tanks...especially since shrimp and shrimp babies can get stuck in it. I don't have a problem when people sell hair algae and call it that, but calling it "wispy moss" or "fairy moss" or whatever is just deceptive. Anyway, it won't harm your tank and pretty much does the same job as any other plant other than being possibly dangerous for a few shrimp here and there (and even more dangerous once you have tiny babies that you will remove within the hair algae once you start pruning it...guaranteed.).

If your tank is going well and reproducing, I wouldn't change anything. If you don't like the cyanobacteria, just remove it. I don't think removing it will mess things up.

[augustus4842]

Hello fellow shrimp parents!

It's been a few months and the ucky black "wispy moss" and black sand is really getting to me. As usual the adult shrimp don't seem bothered by it, but I suspect it maybe the reason my baby shrimp keep dying. In the 3 years I've had the wine glass tank, none of the larvae have survived longer than 2 weeks.
I set up a new tank with some of Mustafa's macroalgae and now have 4 larvae swimming about, they are almost 3 weeks old. This tank is less than 6 months old.

I would like to go about dumping all of the sand and "wispy moss".
Some questions:

1. I have some corals with algae growing on it, do you think I can save those or should i pitch it just in case I can't get all the moss off of it?

2. I bought some black National Geographic aquarium sand from Petsmart http://www.petsmart.com/on/demandware.s ... lor=White
After I bought it, I read terrifying reviews about it raising the PH of the water to 8.8 I do not have anything to measure PH. Is 8.8 too high for shrimp? Or should I go get the same stuff I had before: CaribSea Super Naturals Premium Aquarium Substrate http://www.petsmart.com/fish/supplies/d ... id=300072 I really want black sand, I think it would look cool! But I don't want a 20# bag...

3. I would like to try to save as much of the water as possible. But I will inevitably lose some. Do I have to cycle the additional water before adding it? Or can I just add fresh half salinity (reef salt) distilled water? I imagine I wouldn't replace more than 25-30% of the water.

On an unrelated note, I wonder when Mustafa will have white shrimp for sale!! Hint hint wink

[Mustafa]

You can try to remove the hair algae by hand continuously and at some point it will go away, especially if you have macroalgae competing with it and stop feeding to get nutrient levels down. I don't see any reason to remove the substrate or the corals.

As for the reputedly pH raising sand...don't worry about it. Just rinse it thoroughly and it should be fine...as long as it's natural sand and not coated with something. Some coats are ok...but I wouldn't risk it.

And finally, you don't cycle the water. You let the tank itself mature. So, yes, you can just add newly mixed water directly into your already matured tank. ("old" water of course has microorganisms in it that help mature a tank...but you already have some of that).

As for the white shrimp...I'm not done with my search for them, yet, but I can't seem to find any with the green saddles/eggs that I used to see. So...unfortunately, they won't be offered for sale anytime soon. But then...there are always the yellow/orange ones that are true breeding. But even those will not be offered until probably next year.