Is this algae? - Yes, it is BGA

[bossteck]

Not sure if this is algae, hence posting in aquatalk. Mods, kindly asssist in shifting to the right thread if it should not be here, thanks!

My tank is currently sitting between my living room and dinning room. One side of it gets very diffused sunlight from my windows about 8 meters away.

Here's the side that's getting the sun.



And here's the side that's not getting the sun.



Stand by for dumb questions.....

So... is the black stuff that's under my gravel at the side of the tank algae? If so, what will be the recommended course of action?

Thanks for any response.

[|squee|]

It's BGA, but it's really no problem because it stays under the gravel.

[bossteck]

Hi Terence,

Thanks!
Main cause of BGA is excess food right? Would it go away if I were to reduce my feeding?

[|squee|]

Er, for me BGA is caused by very poor water flow in the affected area.

You might find this interesting.

[KeIgO86]

how about doing a "black out" confined to the gravel area. Use black tape or any other similar light blocking alternatives and cover up the area below the gravel line for several days.

[carlfsk]

how about doing a "black out" confined to the gravel area. Use black tape or any other similar light blocking alternatives and cover up the area below the gravel line for several days.

But I think the lights also seeps through the glass panel to reach the algae.

One way maybe can cover the higher part of the glass too, ard 3-5inches above the gravel, to prevent the lights to reach the algae.

My boss tank also have BGA. We covered the whole tank for a few days and it's gone. But now it comes back again. Read somewhere that it's lack of nitrate in the tank. His tank only got 3 fishes. I wonder if the nitrate thingy is true.

[bossteck]

Hi,

Thanks guys for the suggestions, and Terenece for the useful link!
Think I will just cover the gravel line as suggested.
Will report back in, say... 2 weeks?

P.S. Thanks for shifting the post to the correct folder as well!

[valice]

Have you guys noticed that BGA can also form on the leaves of floating plants? Why does that happen?

[|squee|]

Really? I've never heard of that. Maybe it's the lack of water flow again, from some searching on google.com.

[Justikanz]

I will have/had BGA growing on:

1) Floating leaves
2) Leaves/stems that are too long and hit and congregate at the water surface
3) Land to water area for vivariums
4) Between substrate (usually soil) and tank glass
5) Land edge (vivariums) right next to glass.

Any idea?

[carlfsk]

BGA are some kind of bacteria, cyanobacteria. So I guess they can grow on anywhere.

I'm skeptical when they says they grow only in slow flow area. Mine it actually grows just in front of the fast flowing output of the filter.

[StanChung]

It grows in drains with fast flow too. I think one of the conditions needed are oxygen starved water.

[SmallFish]

oxygen starved ==>> so BGA = anaerobic bacteria ?

[bossteck]

Hi folks,

This is me checking back. After 2 weeks of blackout, coupled with the recent raining weather (less sun), I removed the cardboard I had blocking the substrate... absolutely no difference.

Maybe I am doing it wrong? I didn't chance my tank lighting though. Kinda disappointed.

I am reluctant to dose anything into my tank as I am keeping mostly crypts and am worried about them rotting. I will continue with the blackout and report back.. say after Chinese New Year.

[Simon]

sorry to say but blackout doesn't stop BGA, improve circulation is the solution here. Could be the substrate has turn anaerobic, use a tweezer and poke the substrate, if air bubble emerges from it, then most likely your substrate has turn anaerobic. You will also notice a foul smell from the bubble as well. This is cause by over-compacted substrate

[|squee|]

To add on BGA isn't an algae at all... it's a cyanobacteria.

[Ah_ZhaN]

It grows in drains with fast flow too. I think one of the conditions needed are oxygen starved water.

Is that partly the reason why Peter and Tom Barr emphasize on general water surface movement - to start off with high oxygen level ??

[carlfsk]

But my boss tank's BGA is cleared after a few days of blackout (covering up the whole tank).

So it seems blackout does helps to clear BGA. However, on another note, BGA is a bacteria, how will a blackout help in anyway to clear it?

Ponder.

[|squee|]

Ok I must sound really contradictory here, but to kill off BGA you need a combination of a blackout, improved circulation and a reasonable level of nitrates. I don't want to think about how BGA can be killed by a blackout or not, but here's Tom's method that I've used before:

Add 1/4 teaspoon of KNO3 per 80 liters of tank after the first water change.

Blackout the tank, turn off CO2.

Wait 3 days, do another water change, add same amount of KNO3 back again. Reconnect CO2. Clean filter etc.

Add KNO3 at least 2x a week, 1/8-1/4 teaspoon per 80 liters.

BGA should not come back if you do this.

Regards,
Tom Barr

In addition, the blackout he means is a complete covering of the tank. Take a few thrash bags and tape them to the four sides of the tank as well as the top. Run an airpump if you feel uncomfortable.

[PeterGwee]

Time to vac the substrate to remove the excess "mulm" buildup. "Mulm" in a new tank is good since it has little but too much in an established tank is a drain on O2 and that coupled with low DO and lack of flow/water movement (substrate) creates an environment for cyano-bacteria.

Regards,
Peter Gwee