Bacterial Bloom In Marine

[petertr]

A friend of mine has a Fish Only setup, with 3 fish in it - 2 are about 4" in length, and there is a small moray (? ) eel (8")

Its a 400L tank and also has a large (looks big to me) protein skimmer.


Its been established for a couple of months.
However, he seems to have a bacteria bloom at the moment. How can he deal with that?

TIA

 

[ben1987]

How do you mean?
if you mean cyano, cut lighting and lower phosphate as they are the two things it feeds on

 

[Truck]

correct me if incorect buy morays arent marine are they? i thought they were mid-high end brackish

 

[ben1987]

Moray eels are cosmopolitan, found in tropical and temperate seas.

Morays usually live in warm waters, and subtropical coral reefs to depths of 150 m, where they spend most of their time concealed inside crevices and alcoves.

 

[Truck]

cool

 

[petertr]

No idea about the fish - not my tank and marine isn't my thing.

Symptom was described to me as:

A - 1 extra fish was added - Nitrite level started to rise
B - Extra fish returned to LFS, water changes to bring Nitrite back to zero
C - Nitrate stable, but water started to become cloudy

It's now quite cloudy and I've been told it looks very much like a freshwater bacterial bloom - can you even get those in SW??? If not, what else could it be?


Advise appreciated, as a LFS has already started to talk him into buying chemical additives

 

[SkiFletch]

If it looks like a white cloud then it's likely calcium carbonate precipitate. His pH probably fluctuated a little too much during the water changes and calcium and carbonate ions precipitated out of the water and became micro fine salts in the aquarium causing the cloudiness. The fix for this is to increase surface agitation by adding a pump pointing along the surface of the water. In really bad cases you may have to use an airstone to fix the problem.

DO NOT, I repeat, DO NOT add vinegar or any other acid to the tank. You can really screw yourself over if you dose too much of it and end up causing a real (but unseen) bacterial bloom which eats the acetate AND Oxygen at the same time, consequently suffocating the fish. Trust me on this one, it sounds ridiculous but surface agitation, an airstone, and some patience will fix it. As long as there are no corals in the tank, the cloudiness is not harmful

 

[petertr]

Why would there have been a pH fluctuation?

He only used RO water with the marine salts added. I can't think of anything in the tank that would change the pH of the tank water, and the water being added is 100% spot on.

Confused ???

 

[ben1987]

Lack of oxygen?

 

[rabbut]

Too much CO2, Low Mg in water, low Alk, high nitrate, nitrite, some acid getting into the tank, not enough surface agetation are all the obvious ones. Lack of oxygen should not crash the pH, though low oxygen levels are associated with high CO2 levels if live stock is in the tank and there isn't enough surface gas exchange going on...

In short, there are too many variables that could lead to a pH crash, to diagnose the caurse without some tank stats and history

All the best
Rabbut

 

[petertr]

So we should test the pH then, that would probably help, right?

 

[SkiFletch]

pH testing would have been useful around the time of the waterchanges but it's kind of a moot point at the moment. The most likely reason for pH to have fluctuated would be CO2 and/or not quite fully mixed saltwater which often happens when water changes are done in haste . Combine a little pH fluctuation with waterchanging and having imbalanced calc/alk/mag and you can have a precipitation effect. Like I said before, don't freak out if there aren't corals in the tank, the precipitate is not harmful to fish. Get that surface really agitated and if you have to, stick an airstone in there and you should be fine.

 

[petertr]

pH testing would have been useful around the time of the waterchanges but it's kind of a moot point at the moment. The most likely reason for pH to have fluctuated would be CO2 and/or not quite fully mixed saltwater which often happens when water changes are done in haste . Combine a little pH fluctuation with waterchanging and having imbalanced calc/alk/mag and you can have a precipitation effect. Like I said before, don't freak out if there aren't corals in the tank, the precipitate is not harmful to fish. Get that surface really agitated and if you have to, stick an airstone in there and you should be fine.

Thanks for your replies - I will pass it on.