'Microscopic' creatures

[Liz89]

I'm posting this on behalf of my friend. They have a Marina 35l with a few celestial danios, a few cherry shrimp and a random amano shrimp that was accidentally put in the bag with the cherry's, and an assassin snail and 3 6 week old guppies. A few hours ago a cloud of tiny UMO's (Unidentified moving organisms) appeared. By tiny, we're talking they are in their billions and we're initially mistaken for a bacteria bloom but on closer inspection they are moving around and an occasional 'white dot' darts around a bit. We have never seen anything like this before, we (once discovered they were actually living things) that it might be shrimp fry but have since discovered they have between 5-50 kids so it's not them. What does everyone think? Is it dangerous? how do they fix it?

Thanks, for your advice!

 

[TropicalFishForums]

[bwarwicker]

Could it be larvae from some sort of bug, Mosquitos or something similar, just very time. I will be intrigued if anybody has an answer for this.

[yorkiemad00]

Could be copepods, perhaps something such as cyclops. Little crustaceans.

I had some little white things when I finished cycling but they seem to have been eaten by the fish I added pretty quickly. they seemed to swim in erratic bursts.  Saw most of the around my bogwood.

[MartF]

It sounds like a bloom of Copepods, tiny little creatures that feed on algae. They are more often found in marine aquariums where they are actually encouraged, many years ago I bred Seahorses and raised Copepods as food for the fry.

However, when they appear in a freshwater aquarium it usually indicates a hygiene problem or more often in a tank that's not finished cycling. Do you know if it's a new set up or not?

They are not usually a problem but in rare instances they have been known to spread a tapeworm to fish, but that's extremely rare. There's a lot of info on the web, such as this: http://www.aquarium-pond-answers.com/2006/11/cyclops-are-these-freshwater-copepods.html but there are a lot of different types, the photo is of the most common type.

[Liz89]

It could be that in the picture, MartF, but to know for definite I would have to have a microscope.... They really are THAT tiny! When I say in their billions, I would say I'm not exaggerating (it's atleast millions, definitely!)....

Does the fact that I have now emphasised just HOW small they are, change your opinion or do you still think it's them. I am gutted I can't put a picture up, but there is NO way ANY commercial camera would pick these up.... I need David Attenbourgh and a microscope!! Lol.

The friends in question are only concerned incase they were dangerous to the fish, so hopefully they are what you guys think 

The fish in the tank are ot interested in them really. Does this mean it's something else or would they just not bother eating them because they're so tiny?? They also don't seem to avoid them.

And yes, MartF, it is a new setup, but it was properly cycled before the addition of fish, and we have tested their water for them a couple of times since then too....

Thanks for the help so far....

[MartF]

Yes, when they first hatch they are just like a cloud, microscopic, as you said - but as they feed they grow! At the current stage they are probably too small to attract the fish but they will as they grow bigger. As I said they only usually appear in the latter stages of a cycle but I heard recently that they can be sometimes introduced with live food. Another source of contamination could be when adding new fish and tipping the water out of the bag from the LFS into the tank.They will die off or get eaten but I would look closely at the substrate and make sure it's clean and check the fish are not being overfed, hygiene can be a cause. A good water change would get rid of a lot of them. There are hundreds of different types so they may not all look exactly like the ones in the photo.

[Liz89]

Thank you 

She has said that the cloud is decreasing in density, so maybe they are getting eaten already.... I will tell her to do a 'no feed' day or 2.... Right?

Thaks again

[jackiemcg34]

aye looks like they are getting free food anyway
will you be testing her water? I would just keep an eye on it to make sure no spikes or pwc according

[Liz89]

She is getting her own testing kit in a few days but I have been testing it just to make sure cycle had completed, etc. She has since said the cloud is now completely gone. She didn't feed the tank for 2 or 3 days so I think that helped the fish to become interested, haha.

So problem solved. Thaks for all the help