Bacterial problem

[janner]

Hello,

Small problem with my nano CRS-shrimp tank.
Things seems to go well, if I do daily WC 25% or every other day WC 50%. If I don't, the bacterias will attack. First comes the surface film, the Eisenbacteria (Iron bacteria) and then the Cyanobacteria (BGA). Summer is coming with it's holidays, so I really would appericiate any ideas, how to get longer WC interval.

The tank is established 5 months ago and is 35l/9g Arcadia Arctank, 2x Arcpod 11W (8h/day), ADA PowerSand, ADA Amazonia.
The bottom is covered with HC (thanks Tom for the emerged method, worked great ).
Arctank's original filter is replaced with Sera F400 -internal filter, capacity of up to 400l/h and pointed towards the surface (very good surfase circulation). CO2 injection 1 bubble / every 3 sec.
Temp 25C, pH 7,0, KH 4. EasyLife FFM, Seachem Flourish, Seachem Flourish Excel and now Seachem Stability. Sometimes 1 pumpstroke of AquaArt Macro for keeping the NO3-levels adequate (and Dusko wrote in his blog that BGA does not like NO3). CRS only, so feeding is minimal. Any ideas please, what to do?

 

[Tug]

I had a small outbreak of BGA from elevated levels of ammonia, too much light from a window across the room and poor water circulation in the area of the BGA. Keep your nitrate levels around 20 ppm. Use gaff tape along the glass were you find BGA growing to block out light and improve on the water circulation. I also found that my CRS could live with copper levels up to 0.09 ppm. Copper levels of 0.1 ppm will stop most algae problems but I'm not sure about BGA.

 

[Philosophos]

I think eisenbacteria is a bit of a misnomer that pops up now and then. It can look the same, but odds are it's not what you have. Does it correlate with water changes and feeding or iron dosing? Does it start to turn a rusty color after long enough?

Most of the time what you're seeing are phospholipids and proteins. Take the hydrophobic state of most phospholipids, tack on their ability to act as a floculent in some ways, and you've got surface scum.

How clean is this tank? How much of the food gets eaten? Does some of it float around for a long while?

Pics are always nice.

-Philosophos

 

[janner]

The food gets eaten very quickly and only sinking food is used. Like now, Hayashi Red Bee Shrimp Food, only one piece per day. The original filter was changed to bigger to create a) better filtration and b) good water circulation, so these things are fine (IMO).
Try to keep it quite clean because of high crade shrimps.
Yes, the tank gets some rays of the morning sun, so I can try to prevent this next.

Here's a pic:

 

[Philosophos]

That's a nice little tank.

Looks clean, and easy to keep that way.

Maybe it's the number of shrimp; they've got horribly inefficient digestive systems, so the food may be coming out the other end with such a consistency that it breaks down and adds to the surface film.

-Philosophos