A Cyanobacteria Question

[Akasha72]

As the title suggests I've got a question about cyanobacteria - or blue/green algae
 
I've had it before in an old tank and a 5 day complete blackout did the trick. This time it's different and I'm not sure how to tackle it.
 
This time it's under the substrate line at the front of the tank in two spots. I've tried to photograph it but it's not really showing up too well.
 

 
 
What I want to know is - how do I get rid of it from here? It's not anywhere else in the tank - just at the front under the substrate. I've been considering covering the spots with some thick white paper as I'm guessing it's the sunlight that's caused it but I don't know if I'd be better blacking out the whole tank. Also blacking out the tank is gonna affect the plants which are just starting to bounce back from being torn up back in July when I had to strip the tank to move it.
 
I could use another mind over this as to the best way to tackle it in this odd situation

 

[Ch4rlie]

I had similar to that in my tank, I simply sucked up as much of the 'green' sand using a syphon and disposing of that, and replaced the small amount of sand, it has not come back to date yet.
 
But not a bad suggestion to cover up the lower part of the tank /sand as this would block sunlight but would not look very pretty, depending on how you do that I suppose. Not a method I have tried so do not know if that works or not.

 

[Akasha72]

thanks ch4rlie, I've never ever seen it like this. I've seen it over plants, substrate and decor but never under the substrate so it's good to know someone else has had it
 
Shall I try folding up some like paper or thin card and just cover it and see what happens? Bit of an experiment?

 

[Ch4rlie]

Go for it, see what happens as I would like to know myself if it works then I can offer this as an alternative for anyone who has this occurring.
 
Of course for those reading this too

 

[Akasha72]

yeah, that's what I was thinking too. 

 

[gmc1]

Got it in my 90 litre.taking ages to dispearse.ajusting flow and lowering nitrates.was easier in my big tank.i swear once my little tanks clean it watches for me leaving the room till its back.lol

 

[Bubbelzzz]

This happens more often actually. I've had it too.
Covering it with some tape for a while will do the trick for the most tanks. But of course you could also use the suggestion of Ch4rlie as it is just a small amount.

 

[Akasha72]

I've been out for the day and I've not been home long so I've not had chance to deal with it today. I have a recycling bag full of the thin cardboard that comes from food packaging. Tomorrow I plan to cut some bits from them and cover the area's on the tank. Thin card should block out more light than paper so I'm hoping it will rid my tank of this horrible stuff
 
I'll let you know if it works

 

[Akasha72]

I've now covered the entire base at the front with bits of thin card - I decided to black it out all the way along rather than just cover where the cyanobacteria is because I fear it will just move to a new spot. I've covered the entire front about 4 inches up from the base and then covered the card with 2 layers of masking tape. The tank looks a mess but I plan to leave it like that for a week now.
 
I'll report back and let you all know if this works or if I'm looking at a complete tank blackout to get rid of it

 

[Akasha72]

Just an update on this.
 
So I took the wraps off the tank today as it's been 7 days and the cyanobacteria is still there, no change at all.
 
So, now I've got two choices. Either do a complete blackout or do as Ch4rlie said and try and suck it out somehow. Not sure which to try

 

[Ltygress]

I would try Ch4rlie's suggestion first. That one won't kill your plants off or make them die off/"melt" back.

 

[gmc1]

Mines starting to subside on my small tank akasha.syphoning what I can along with 50% water changes.I did add a temp small powerhead for more flow along the bottom but don't know if it helped.

 

[Akasha72]

thanks guys. I have a syphon that sucks debris into a cotton bag meaning no need to top up water. I'm going to dig that out today and try using that to suck out the affected sand. I can then just throw away the sand as I have a small bag of fresh sand in stock so I can just top it back up with fresh
 
I'll let you know if this gets rid of it or whether it just comes back

 

[Ch4rlie]

sounds good, keep us updated

 

[Akasha72]

I sucked out as much of it as I could get to and threw away the affected sand. It exposed the glass and the other 'normal' green algae that was there and my SAE's loved that! They were fighting over it to eat it! 
 
We'll see how it goes now and yes, I'll keep things updated